Distribution of blood lead and cadmium levels in healthy children aged 0 to 18 years and analysis of related influencing factors in Henan, China: data findings from 2017 to 2022

BACKGROUND

There is still a lack of data on blood lead levels (BLLs) and blood lead levels (BLLs) in healthy children of all ages from 0 to 18 years in China. This study was performed to analyze the BLLs and BCLs in healthy children aged 0-18 years from 2017 to 2022 in urban and rural areas of Henan Province, Central China, as well as their relationships with socio-demographic variables and certain relevant exposure factors. To provide a basis for evaluating public health policy development and exposure risk management.

METHODS

This was an observational study containing data from 17 prefecture-level cities in Henan, China. Blood Pb and Cd levels were determined using a triple quadrupole inductively coupled plasma mass spectrometer equipped with an autosampler. We first calculated the concentrations of Pb and Cd elements in participants of different genders, ages and years, and then created visual graphs depicting the distribution of each element in terms of gender, age and year (2017-2022). The rates between different groups were compared using the Chi-square test or Fisher exact test (if applicable). The means were compared by one-way ANOVA, medians were compared with the Kruskal-Wallis rank-sum test. Generalized linear models (GLM) were performed to estimate the effects of various factors on blood Pb and Cd concentrations in children.

RESULTS

We recruited a total of 25,920 children (16,142 boys and 9,778 girls) aged 0.01 to 18.00 years (2.58 (1.00,6.25)). The median of BLLs was 23.48µg/L, around 9.39% of studied children had elevated BLLs. The median of BCLs was 0.66µg/L, around 1.84% of studied children had elevated BCLs. The median blood Pb concentration was higher in boys (23.90µg/L) than in girls (22.75µg/L) (P<0.001). The median blood Pb concentration was highest in the 3-7 years group (24.51µg/L) and the median blood Cd concentration was highest in the 1-3 years group (0.66µg/L) among all age groups. Both BLLs and BCLs were substantially higher in children in 2020-2022 compared to 2017-2019. Rural children had lower BLLs and higher BCLs. The results of the generalized linear model showed that children in households using Oil, coal, pellet or other wood as a fuel for heating, children with higher frequency of exposure to tobacco smoke and beverage intake had significantly increased chances of elevated BLLs and BCLs.

CONCLUSIONS

Pb and Cd exposure of children in this area is relatively low, but associated risk factors continue to exist in vulnerable populations. This study is the first big data analysis of Pb and Cd in children in Henan, China, and provides baseline information for future research.

Unraveling the interaction between lead and calcium in occupationally exposed males: an exploratory observation study

OBJECTIVE

The systemic illnesses associated with chronic lead exposure are partially explained by the interaction between lead and calcium metabolism. Lead exposure is posited to alter calcium levels either by altering calcium homeostasis markers or altering bone remodeling. The present study investigated the interaction between blood lead levels and calcium homeostasis markers and bone remodeling markers among lead-smelting plant workers.

METHOD

Adult male workers employed at the lead-smelting plant were clinically investigated as part of their regular occupational health assessment program. Additionally, control participants without occupational lead exposure, employed in administrative and white-collar jobs were invited to participate in the study. Sociodemographic and occupational details were collected by pre-standardized semi-structured questionnaires from all consenting participants, followed by clinical examination and blood collection. Blood lead levels were estimated using microwave-assisted acid digestion and the inductively coupled plasma mass spectrometry technique. Serum calcium and total protein and alkaline phosphatase levels were estimated as per standard biochemical techniques. 25-hydroxy vitamin-D3, calcitriol, and osteocalcin were estimated using the enzyme-linked immunosorbent assay. In addition to comparative analysis for comparing the two groups, independent linear regression models were explored to investigate the associations between serum calcium and blood lead and osteocalcin levels.

RESULT

A total of 189 lead-exposed men employed at the lead-smelting plant and 25 male control participants consented to participate. The two groups were similar in age, diet, and body mass index. Occupationally exposed individuals exhibited significantly lower serum calcium and higher bone remodeling markers (osteocalcin and alkaline phosphatase) as compared to controls. However, the serum 25-hydroxy vitamin-D3 and calcitriol levels were not significantly different between the two groups. Lastly, the serum lead and osteocalcin were weakly but significantly associated with serum calcium levels after controlling for variations in total protein, diet, 25-hydroxy vitamin-D3, calcitriol, and alkaline phosphatase in the study participants.

CONCLUSION

Current observations reinforce the adverse role of lead exposure on calcium metabolism. Although lead exposure is posited to affect calcium metabolism by multiple pathways, current study observations favor the bone remodeling pathway. The observations recommend periodic screening for calcium and bone health among lead-exposed adults.

Impact of DNA repair polymorphisms on DNA instability biomarkers induced by lead (Pb) in workers exposed to the metal

Although the mechanisms of Pb-induced genotoxicity are well established, a wide individual's variation response is seen in biomarkers related to Pb toxicity, despite similar levels of metal exposure. This may be related to intrinsic variations, such as genetic polymorphisms; moreover, very little is known about the impact of genetic variations related to DNA repair system on DNA instability induced by Pb. In this context, the present study aimed to assess the impact of SNPs in enzymes related to DNA repair system on biomarkers related to acute toxicity and DNA damage induced by Pb exposure, in individuals occupationally exposed to the metal. A cross-sectional study was run with 154 adults (males, >18 years) from an automotive batteries' factory, in Brazil. Blood lead levels (BLL) were determined by ICP-MS; biomarkers related to acute toxicity and DNA instability were monitored by the buccal micronucleus cytome (BMNCyt) assay and genotyping of polymorphisms of MLH1 (rs1799977), OGG1 (rs1052133), PARP1 (rs1136410), XPA (rs1800975), XPC (rs2228000) and XRCC1 (rs25487) were performed by TaqMan assays. BLL ranged from 2.0 to 51 μg dL^-1 (mean 20 ± 12 μg dL^-1) and significant associations between BLL and BMNCyt biomarkers related to cellular proliferation and cytokinetic, cell death and DNA damage were observed. Furthermore, SNPs from the OGG1, XPA and XPC genes were able to modulate interactions in nuclear bud formation (NBUDs) and micronucleus (MNi) events. Taken together, our data provide further evidence that polymorphisms related to DNA repair pathways may modulate Pb-induced DNA damage; studies that investigate the association between injuries to genetic material and susceptibilities in the workplace can provide additional information on the etiology of diseases and the determination of environmentally responsive genes.

Blood lead levels of children exposed to e-waste: a systematic review and meta-analysis

Blood lead levels (BLLs) have been decreasing worldwide for decades. However, systematic reviews and quantitative syntheses of BLLs in electronic waste (e-waste)-exposed children are lacking. To summarize temporal trend of BLLs among children in e-waste-recycling areas. Fifty-one studies met the inclusion criteria and included participants from six countries. Meta-analysis was performed using the random-effects model. Results showed that among e-waste-exposed children, the total geometric mean (GM) BLL was 7.54 μg/dL (95% CI: 6.77, 8.31). Children's BLLs displayed a decreasing temporal trend, from 11.77 μg/dL in phase I (2004-2006) to 4.63 μg/dL in phase V (2016-2018). Almost 95% of eligible studies found that children exposed to e-waste had significantly higher BLLs than reference groups. The difference of children's BLLs between the exposure group and the reference group was from 6.60 μg/dL (95% CI: 6.14, 7.05) in 2004 to 1.99 μg/dL (95% CI: 1.61, 2.36) in 2018. For subgroup analyses, except for Dhaka and Montevideo, the BLLs of children from Guiyu in the same survey year were higher than those of children from other regions. Our findings indicate that the gap between BLLs of children exposed to e-waste and those of reference group children is closing, and we appeal that the critical value for blood lead poisoning in children should be lowered in key e-waste-dismantling areas of developing countries, such as Guiyu.

Development and validation of Graphite Furnace Atomic Absorption Spectrometry method and its application for clinical evaluation of blood lead levels among occupationally exposed lead smelting plant workers

The growing interest in estimating the blood lead levels, for early detection of lead exposure, warranted a need for a validated analytical method for trace levels estimation of lead. The present study aimed to develop an analytical method for detecting trace amounts to elevated levels of lead in human blood using the Graphite Furnace Atomic Absorption Spectrometry technique and its application in evaluating blood lead levels among occupationally exposed individuals. The method validation was performed with standard test parameters including linearity, recovery, precision, method detection limit, and limit of quantification. The validation results for each performance parameter were in agreement with acceptable criteria as per standard guidelines. The correlation was observed as optimum linear (R² = 0.998) between absorbance and lead concentration range from 0 to 10 µg/dL. The recoveries for spiked samples ranged between 95 and 105%. The calculated value for the method detection limit was 0.16 µg/dL and the limit of quantification was 0.51 µg/dL. The precision for all spiked concentrations was below 10% of the relative standard deviation. Evaluation of lead exposure among occupationally exposed individuals revealed the study population had found average blood lead level (42.80 ± 12.47 µg/dL), which was above the upper acceptable limit suggested by Occupational Safety and Health Administration, USA. The majority of system-specific symptoms were observed among study groups having mean blood lead levels above 40 µg/dL. However, sociodemographic status and employment factors were found possible determinants of the prevalence of high blood lead levels.

The construction and validation of a lead exposure screening tool for pregnant women in Thailand (ThaiL8Is)

Objectives

To construct, validate, and implement a new screening tool for lead exposure in Thai pregnant women.

Methods

A cross-sectional study that included three processes: screening tool development, validation, and implementation. The participants were pregnant women who had received antenatal care at district health promotion hospitals. There were 100 pregnant women in Nakhon Si Thammarat province during the validation process, and 30 pregnant women in Phang Nga province during the implementation process. Blood lead levels (BLLs) were analysed by atomic absorption spectrophotometry. The sensitivity and specificity of the screening instrument, as well as the Area Under the Curve (AUC), demonstrate its validity.

Results

There were 80 BLL-related items found through the collection of primary and secondary data and examined for validity and inter-rater reliability by five experts. Six items were excluded because the values were less than the criteria set. Seventy-four items remained with the Item Content Validity Index (I-CVI) = 0.80-1.00, the Content Validity Index Average (S-CVI/Ave) = 0.91, and Kappa scores = 0.76-1.00. After using 74 items collected on pregnant women, only 31 items were included in the validation process. Following that, the pooled eight items with cut-off point scores of 1 had the highest validity, which included systolic blood pressure, diastolic blood pressure, urine sugar, haemoglobin level, occupation, drinking coffee, using chemical products, and education level (ThaiL8Is). The ThaiL8Is in the validation process yielded sensitivity = 80.9%, specificity = 69.8%, and an AUC (95%CI) = 0.78 (0.69-0.87). The implementation process has confirmed the validity of the screening tool; sensitivity = 78.9%, specificity = 81.8%, and the AUC (95%CI) = 0.80 (0.63-0.97).

Conclusions

The ThaiL8Is a valid screening tool for Thai pregnant women. ThaiL8Is' sensitivity in detecting the risk groups for lead exposure can be enhanced by a combination of biochemical markers used in routine prenatal screening. It can be used to screen pregnant women for early indicators of lead exposure prior to a blood lead test.

Biomarkers of maternal lead exposure during pregnancy using micro-spatial child deciduous dentine measurements

BACKGROUND

Lead is a toxic chemical of public health concern, however limited biomarkers are able to reconstruct prior lead exposures in early-life when biospecimens are not collected and stored. Although child tooth dentine measurements accurately assess past child perinatal lead exposure, it has not been established if they reflect maternal exposure in pregnancy.

AIM

To assess the prenatal relationship between child tooth dentine and maternal blood lead measurements and to estimate maternal lead exposure during the 2nd and 3rd trimesters of pregnancy from weekly child dentine profiles.

METHODS

We measured early-life lead exposure in child tooth dentine and maternal blood from 419 child-mother dyads enrolled in the Programming Research in Obesity, Growth, Environment and Social Stress (PROGRESS) cohort. We employed the Super-Learner algorithm to determine the relationship of dentine lead data with maternal blood lead concentrations and to predict maternal lead from child dentine lead data in blinded analyses. We validated and quantified the bias of our results internally.

RESULTS

Mothers had moderate blood lead levels (trimesters: 2nd = 29.45 ug/L, 3rd = 31.78 ug/L). Trimester-averaged and weekly child dentine lead measurements were highly correlated with maternal blood levels in the corresponding trimesters. The predicted trimester-specific maternal lead levels were significantly correlated with actual measured blood values (trimesters: 2nd = 0.83; 3rd = 0.88). Biomarkers of maternal lead exposure discriminated women highly exposed to lead (>mean) with 85 % and 96 % specificity in the 2nd and 3rd trimesters, respectively, with 80 % sensitivity.

DISCUSSION

Weekly child dentine lead levels can serve as biomarkers of past child and maternal lead exposures during pregnancy.

Longitudinal association of early childhood lead exposure and adolescent heart rate variability: influence of parental education

Lead exposure has been shown to dysregulate physiological stress responses. However, few studies have investigated the effect of lead exposure on later heart rate variability (HRV), an indicator of a stress response, in large samples of children. Furthermore, the interaction between social environmental factors and lead exposure in childhood, which commonly co-occur, remains understudied. This study examined relationships between childhood lead exposure and early adolescent physiological stress responses at different levels of parental education. Participants were 406 children from Jintan, China. Blood lead levels (BLLs) and parental education data were collected at 3-5 years of age, and HRV outcomes assessed at 12 years via frequency domain measures (LF/HF ratio) collected during an induced stress test. Results show a significant interaction between parental education and BLLs at 3-5 years. This relationship was found to be most consistent for the interaction between BLLs and mother's years of education for both the planning (β = 0.12, p = 0.046) and speaking (β = 0.11, p = 0.043) phase of the stress task, suggesting that increasing years of mother's education may enhance the deleterious influence of lead exposure on the HRV frequency measure, LF/HF ratio. This research highlights the complexity in lead exposure induced outcomes.

Role of environmental lead in the occurrence of anemia in Indian children: a systematic review and meta-analysis

Exposure to lead among children, as well as adults, is a major global health issue. With diverse routes of exposure (e.g., food, air, and water) either environmentally or occupationally, lead among children can cause mild, moderate, to severe health complications in the later stages of life. The average blood lead level reported by CDC in 2021 is 3.5 µg/dL, and the level of blood lead toxicity is ≥ 10 μg/dL. In this study, we planned to systematically analyze the association between blood lead levels (BLLs) (≥ 10 μg/dL and < 10 μg/dL) and the risk of anemia (hemoglobin level < 11 g/dL) among Indian children aged between ≥ 1 and ≤ 18 years. An online literature search of 5 databases, PubMed, Ovid, EMBASE, Web of Science, and Google Scholar was accomplished with a search updated until 8^th March 2021. Study designs included cohort, cross-sectional, and case-control studies that have evaluated the association of lead toxicity or exposure with anemia (Hb < 11 g/dL) reported in urban and/or rural Indian children. Meta-analysis was performed among a total of 864 children from 4 cross-sectional studies. The association between lead toxicity (BLLs ≥ 10 μg/dL) and the risk of being anemic was not statistically significant (RR = 1.15 (95% CI: 0.86-1.55, I² = 77%). The risks of bias in all included studies were low according to the Newcastle Ottawa Scale. Increased blood lead levels did not appear to be the major contributor to anemia in Indian Children. We need to focus primarily on improving the nutritional quality, fortified food supplements, and a balanced diet for children to reduce the anemia burden in India. Lead toxicity should be sought as an etiological factor only in areas of high environmental risk factors which were leaded paints, leaded batteries, a house near major road/traffic areas, and pesticide exposure.

Early childhood lead exposure and adolescent heart rate variability: A longitudinal cohort study

Lead is a known neurotoxicant with many detrimental health effects, including neurocognitive deficits and cardiovascular and metabolic disorders. However, few studies have tested the association between lead exposure and the physiological stress response, which in and of itself may act as a precursor to and/or underlying mechanism of detrimental health outcomes. The purpose of this study was to examine the influence of early childhood and early adolescent low-level lead exposure on early adolescent heart rate variability, a widely-used measure of physiological stress. Participants were 408 children from Jintan, China for whom blood lead levels were measured between 3 and 5 years (early childhood) and again at 12 years (early adolescence). Heart rate variability was assessed at 12 years while participants underwent an induced stress task utilizing the ratio of low to high frequency (LF/HF) ECG measures. Mean blood lead levels in the cohort were 6.63 mcg/dl and 3.10 mcg/dl at 3-5 years and 12 years, respectively. Blood lead levels at 3-5 years of age (β 0.06, p = 0.027), but not at age 12 (β -0.05, p = 0.465), were significantly associated with LF/HF measures while controlling for multiple sociodemographic variables, potentially reflecting a dysregulated stress response with a shift towards sympathetic dominance. These findings suggest that early childhood lead exposure may have a detrimental influence on early adolescent autonomic responses to acute stress, which holds implications for cardiovascular health and overall growth and development.

Factors associated with blood lead levels in children in Shenyang, China: a cross-sectional study

Background

Although blood lead levels (BLLs) in children are gradually decreasing, low-concentration lead exposure can still exert adverse effects. We studied the factors that affect BLLs in children in Shenyang, China.

Methods

We conducted a cross-sectional study by administering structured questionnaires on family demographics and food intake. The concentrations of lead in venous blood were determined by graphite furnace atomic absorption spectrometry.

Results

A total of 273 children aged 1–6 years were enrolled. The geometric mean (geometric standard deviation) of BLLs was 24.94 (12.70) μg/L in boys and 23.75 (11.34) μg/L in girls. The prevalence of BLLs of ≥35 μg/L was 22.7% and was mainly observed in children aged under 3 years. Often hand washing before meals was protective against BLLs ≥20 μg/L (adjusted OR: 0.427, 95%CI: 0.238–0.767, p = 0.004). Consumption of puffed grains and eggs had an adjusted OR (95%CI) for BLLs ≥20 μg/L of 1.714 (1.012–2.901) (p = 0.045) and 1.787 (1.000–3.192) (p = 0.050), respectively.

Conclusions

BLLs of children in Shenyang are still higher than in developed countries. Consumption of puffed grains and eggs is associated with higher BLLs. Often hand washing before meals may be protective against high BLLs.

A new approach to a legacy concern: Evaluating machine-learned Bayesian networks to predict childhood lead exposure risk from community water systems

Lead in drinking water continues to put children at risk of irreversible neurological impairment. Understanding drinking water system characteristics that influence blood lead levels is needed to prevent ongoing exposures. This study sought to assess the relationship between children's blood lead levels and drinking water system characteristics using machine-learned Bayesian networks. Blood lead records from 2003 to 2017 for 40,742 children in Wake County, North Carolina were matched with the characteristics of 178 community water systems and sociodemographic characteristics of each child's neighborhood. Bayesian networks were machine-learned to evaluate the drinking water variables associated with blood lead levels ≥2 μg/dL and ≥5 μg/dL. The model was used to predict geographic areas and water utilities with increased lead exposure risk. Drinking water characteristics were not significantly associated with children's blood lead levels ≥5 μg/dL but were important predictors of blood lead levels ≥2 μg/dL. Whether 10% of water samples exceeded 2 ppb of lead in the most recent year prior to the blood test was the most important water system predictor and increased the risk of blood lead levels ≥2 μg/dL by 42%. The model achieved an area under the receiver operating characteristic curve of 0.792 (±0.8%) during ten-fold cross validation, indicating good predictive performance. Water system characteristics may thus be used to predict areas that are at risk of higher blood lead levels. Current drinking water regulatory thresholds for lead may be insufficient to detect the levels in drinking water associated with children's blood lead levels.

Mapping blood lead levels in French children due to environmental contamination using a modeling approach

The decrease in levels of lead in air and drinking water over the last 40 years has resulted in an overall decrease in blood lead levels (BLLs). However, there is no known safe level of lead regarding developmental effects in children. This paper maps predicted BLLs of children in France, resulting from a simulated chronic exposure in two steps, with the aim of identifying areas with environmentally overexposed populations. Probabilistic estimates of BLLs based on environmental contamination were obtained and compared to biomonitoring data. First, the contribution of various environmental exposure pathways was estimated using a multimedia exposure model: spatialized data on soil, drinking water and air contamination, together with data on food contamination and ingestion, was joined using geostatistical approaches. In a second step, a Physiologically Based Toxicokinetic (PBTK) model provided estimates of BLLs. Probabilistic estimates of BLLs were obtained by simulating uncertainty and variability of exposure levels, physiological characteristics and lead-specific parameters in the PBTK model. The median and 95th percentile of predicted BLLs in children aged 1 to 11 were compared to recent biomonitoring data obtained in France in young children (SATURNINF study): median predictions were overestimated in infants and in agreement with median observed BLLs in children aged 3 to 6. Upper bounds of predicted BLLs were protective due to uncertainties in exposure estimates. The main source of exposure appeared to be drinking water in children over 2 years old, and vegetal food and milk in children under 2 years old. Although elevated drinking water lead levels were not related to large geographical areas, the relatively fine resolution map also pinpointed geographical areas of concern due to elevated soil lead levels.

Uneven development of the lead industry leads to regional differences in blood lead levels of children

Children's exposure to lead is a global health problem, especially in low- and middle-income countries. However, research on the relationship between children's blood lead levels (BLLs) and the development of the lead industry is still limited. This study examined whether children's BLLs were associated with the development of lead industry in different regions. Using survey data on the BLLs of children living in 250 prefectures in China with corresponding data on their economic factors and lead industries, we explored the regional variation of children's BLLs using statistical methods. The results show that the level of economic development in leaded areas was associated with inequity in children's BLLs and met the environmental Kuznets hypothesis. In areas without lead industries, there was little correlation between the level of economic development and the BLLs of children and thus the environmental Kuznets hypothesis was not supported. Lead mines, lead smelting and chemical companies are major sources of blood lead in children living in leaded areas. This study demonstrated the success of control policies for lead-acid battery manufacturers in promoting the prevention and control of childhood lead poisoning in China. China should consciously support the improvement of children's BLLs in undeveloped areas with lead industries through national financing and policies to avoid the continuous effects of the regional inequality problem of high children's BLLs.

An integrated assessment of lead exposure in children: Correlation with biochemical and haematological indices

BACKGROUND

Lead (Pb) is a worldwide concern due to its persistent property in the environment. However, due to diminutive evidence and elusiveness, the impact of lead exposure on the biochemical and haematological parameter in school-age children is not well established.

AIM

This study primarily aimed to investigate blood lead (BL) in children and its association with haematological and biochemical parameter.

METHODS

A total of 43 children (4-12 years) were recruited in each control and study group. Furthermore, the study group were subdivided into two groups (group A (<10 μg/dl) and group B (>10 μg/dl)). BL level, haematological parameter including haemoglobin, packed cell volume, red blood cells, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, total leukocytes count, neutrophils, lymphocytes, monocytes, mean corpuscular volume, red cell distribution width, eosinophil's, platelets in the whole blood and biochemical parameter such as liver function test (total bilirubin, alkaline phosphatase, serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase, total protein, albumin) and kidney function test (sodium, potassium, blood urea nitrogen, creatinine) in serum were measured using anodic stripping voltammeter (ASV), Cell-Dyn Ruby Haematology analyser, Beckman coulter Unicel Dxc 800 Synchron Clinical analyser respectively.

RESULTS

The arithmetical mean of BL level was 19.93 ± 9.22 μg/dl (median: 17.5 μg/dl; range 9.1-37.4 μg/dl). Only 21 % children had BL levels <10 μg/dl and there were 79 % children with BL levels >10 μg/dl. Blood mean corpuscular haemoglobin concentration, Neutrophils, Monocytes were significantly higher between the control and study group. Additionally, haemoglobin, packed cell volume, red blood cells, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, Lymphocytes and mean corpuscular volume intensities were significantly lower in >10 μg/dl group whereas total leukocytes count, neutrophils, monocytes, red cell distribution width, eosinophil's, platelets levels were statistically higher (p < 0.001). Serum alkaline phosphatase, serum glutamic-oxaloacetic transaminase, total protein, were higher (p < 0.05) and sodium, albumin were significantly lower in the study group. The mean value of sodium, potassium, total bilirubin, alkaline phosphatase, serum glutamic-pyruvic transaminase, total protein and blood urea nitrogen, creatinine in two groups (<10 μg/dl and >10 μg/dl) was not significantly different. Serum glutamic-oxaloacetic transaminase level was significantly higher (p = 0.015) while albumin levels were significantly lower (p = 0.034) in >10 μg/dl group. A statistically significant correlation of BL levels with all haematological parameters was also observed. Creatinine is positively and albumin was negatively correlated with BL levels.

CONCLUSION

The outcomes specify that high BL levels were significantly associated with higher haematological and biochemical indices in exposed children. However, lead like noxious metals severely affected the haematological, kidney and liver health of children.

Evaluation of divalent metal transporter 1 (DMT1) (rs224589) polymorphism on blood lead levels of occupationally exposed individuals

Lead (Pb) is an environmental and public health toxicant. It affects various organ systems of the body, thereby disrupting their normal functions. To date, several genes that are known to influence the mechanism of action of lead and toxicity have been studied. Among them, the iron transporter gene, SLC11A2 (Solute Carrier 11 group A member 2) which codes for the transmembrane protein, DMT1 (Divalent Metal Transporter 1) has shown to transport other metals including zinc, copper, and lead. We investigated the influence of DMT1 polymorphism (rs224589) on blood lead (Pb-B) levels. In the present study, we enrolled 113 lead-exposed workers and performed a comprehensive biochemical analysis and genetic composition. The frequency of DMT1 variants observed in the total subjects (n = 113) was 42 % for homozygous CC wild type, 54 % for heterozygous CA, and 4 % for homozygous AA mutant. The heterozygous CA carriers presented higher Pb-B levels compared to wild type CC and mutant AA carriers. Further, a negative association was observed between Pb-B levels and hemoglobin in heterozygous CA carriers. Hence, C allele may be the risk allele that contributes to increased susceptibility to high Pb-B retention, and genotyping of DMT1 in lead exposed subjects might be used as a prognostic marker to impede organ damage due to lead toxicity.

Blood lead levels in indigenous peoples living close to oil extraction areas in the Peruvian Amazon

BACKGROUND

High blood lead levels (BLLs) have been previously reported in indigenous people living in communities in the northern Peruvian Amazon. Oil extraction activities have been conducted in the area since the 1970s and have been identified as a source of lead exposure.

OBJECTIVE

Measure BLL and assess risk factors associated with BLL among indigenous populations from four river basins of the northern Peruvian Amazon.

METHODS

Participants from 39 communities were selected using a two-stage stratified random selection strategy and were visited between May and June 2016. Information on risk factors was collected using structured questionnaires and blood samples were taken. Overall, complete information was available from 1047 individuals (309 < 12 years old, 738 ≥ 12 years). BLL was determined using atomic absorption spectrophotometry in a graphite chamber. Weighted linear logistic regression models were used to study the association between socio-demographic variables, self-reported life-style factors, environmental, geographical and occupational exposures and BLLs.

RESULTS

Geometric mean (95% CI) BLL was 4.9 (4.5, 5.4) µg/dL in participants <12 years and 5.7 (5.4, 6.0) µg/dL in older participants. There were marked differences in BLL between river basins with the highest levels observed in the Corrientes river basin [8.1 (7.2, 9.1) µg/dL <12 years and 8.8 (8.0, 9.6) µg/dL older participants]. High BLL was associated with older age, being male, living in the Pastaza, Tigre or Corrientes river basins and consumption of fish offal in children and adults. Increased Euclidean distance between residence and oil production facilities was associated with a small reduction in BLL.

CONCLUSION

BLLs that pose a health risk were detected in the study population of a non-industrialized and remote area of the Amazon. The highest BLLs were observed in those river basins where relative oil extraction activity and environmental levels of contaminants have been reported to be greatest.

A probabilistic toxicokinetic modeling approach to the assessment of the impact of daily variations of lead concentrations in tap water from schools and daycares on blood lead levels in children

The aim of this study was to assess the impact of exposure to tap water lead concentration ([Pb]_TW) occurring in schools or daycares on blood lead level (BLL) of attending children. Given the potentially wide variations in space and time of ([Pb]_TW) documented in the literature, a simple probabilistic toxicokinetic (STK) model that allows the simulation of the time-varying evolution of BLL in response to these variations was developed. Thus, basic toxicokinetic equations were assembled to simulate BLL in a typical infant, toddler and pupil. The STK model's steady-state BLL predictions showed good correspondence when validated against Integrated Exposure and Uptake BioKinetic model predictions for comparable [Pb]_TW values. Exposures to three distributions of [Pb]_TW in specific sets of Canadian schools and daycares documented in the scientific literature were simulated probabilistically with Monte Carlo simulations. For the highest distribution of [Pb]_TW simulated (median, 90th percentile = 24, 412 μg/L), average annual BLL (median, 97.5th percentile) varies between 1.5 and 6.4 μg/dL in infant and 1.1 and 3 μg/dL in pupils. Toddler's results were midway between those from the infants and pupils. Under this exposure scenario, the infant may present BLL > 5 μg/dL for a significant number of days over the course of the academic year (median; 97.5th: 17; 227 days). However, peak exposure may remain unnoticed if rare and drowned out by the background BLL. In conclusion, even if they may be sparse, peak exposure episodes to [Pb]_TW in schools and daycares may suffice to increased BLL in attending individuals. This finding emphasizes the need for further characterization of [Pb]_TW in schools and daycares in order to identify potentially problematic institutions and therefore avoid undesirable exposures for the children attending them.

Blood lead levels of Chinese children from 1991 to 2020: Based on Monte Carlo simulation

Chinese children have been exposed to high level of lead due to polluted air, dust, contaminated foods and water, etc. In this research, we investigated published blood lead levels (BLLs) reflecting 1,057,832 Chinese children aged at 0-12 and teenagers aged at 13-18 in the past 30 years (1991-2020). The data mining and estimation were performed innovatively by Monte Carlo simulation to remedy the skewed distribution-induced bias. The temporal trend of Chinese children's BLLs showed an obvious decrease in the past decades from 88.74 μg/L (Geometric SD = 4.09) during 1991-1995 to 27.32 μg/L (Geometric SD = 4.18) during 2016-2020. This study also indicated that children's BLLs of Yunnan, Guizhou, Shanxi were at relatively high levels and most provinces showed a downward trend. Chinese boys aged at 1-18 years old had higher BLLs (GM: 44.03 μg/L) compared to girls (GM: 41.32 μg/L) (p < 0.001). At different age groups, Chinese children's BLLs were 42.04 μg/L (1-3 years old), 52.88 μg/L (4-6 years old), 50.49 μg/L (7 and above years old), respectively. Although the BLLs of Chinese children exhibited a continuous declined trend in the past 30 years, it was still higher than that in developed countries, which indicated that more efforts are needed in children's BLLs control.

Blood lead levels and their associated risk factors in Chinese adults from 1980 to 2018

In China, studies on lead exposure to grownup are scarce compared to children, although relevant disease burdens for adults are much severe than that in developed countries. The present study evaluated blood lead levels (BLLs) in Chinese adults by data mining using Monte Carlo simulation. A total of 115 scientific studies published between January 1980 and March 2021 reflecting 45,514 Chinese adults were included in the study. After a continuous increase in Chinese adult BLLs from 1980-1983 (GM 74.84 μg/L) to 1994-1996 (GM 92.27 μg/L), BLLs began to decline from 2000--2002 (GM 80.32 μg/L) to 2016-2018 (GM 21.57 μg/L). This decline implied that the lead phase-out policy in gasoline was effective over the past two decades. The study indicated that North, South, and Southwest China were still relatively high compared to other regions in the past decade. Statistical analysis showed that BLLs of males (GM 68.45 μg/L) were higher than females (GM 56.51 μg/L), smokers (GM 80.96 μg/L) higher than nonsmokers (GM 58.95 μg/L), and populations over 40 (GM 40.43 μg/L) higher than younger populations (GM 40.37 μg/L). The significantly positive correlation between the concentrations of PM2.5 and topsoil lead and BLLs in Chinese adults indicated that air and soil pollution affect adult BLLs. Taken together, our results showed that strict lead control strategies and regular bio-monitoring are needed to maintain low BLLs in the population.

Blood lead level monitoring related to environmental exposure in the general Iranian population: a systematic review and meta-analysis

Exposure to lead can cause adverse health problems incorporating hypophosphatemia, heart and liver disease, cancers, neurological and cardiovascular diseases, central nervous disorders, and sensory disorders. This study investigated the blood lead level in the general Iranian population with environmental exposure to lead. In the presented systematic review and meta-analysis, the authors searched Iranian dataset, including Magiran, SID, Iranmedex, and Nopa, and the main dataset, comprising PubMed, Scopus, Embase, and Web of Science, all available articles until 12 January 2019, and extracting 55 studies (with 63 data for analysis) to a meta-analysis. A comprehensive meta-analysis software, pooled standard deviation, mean, sample size, and the utterly random effects model was analyzed in this study. The results showed that the overall mean BLL (95% CI) in total inquiries was 6.41 μg/dL (5.96 to 6.87). Besides, the results for gender and age subgroups were as follows: mean BLL, 6.47 μg/dL, 95% CI, 5.79, to 7.15, mean BLL, 6.44 μg/dL, 95% CI, 5.96, to 6.91, respectively. Conclusively the mean BLL in the Iranian population was higher than the recommended level by the US Centers for Disease Control and Prevention (CDC). Results indicated that the mean BLL in men and adults was more elevated than in women and children, respectively. Therefore, BLL monitoring and screening of the general Iranian population are is necessary to determine a reference value.

Association of blood lead levels with preeclampsia: A cohort study in China

BACKGROUND

Preeclampsia is the main cause of maternal and perinatal death, especially in developing countries. Multiple studies suggest that blood lead levels in pregnancy are a risk factor for preeclampsia, even with low levels of blood lead. But less knows the dose-effect relationship of preeclampsia in low blood lead levels.

OBJECTIVES

This study aims to assess the association between blood lead levels and preeclampsia and to explore its dose-effect relationship between low blood lead levels and preeclampsia.

METHODS

The retrospective cohort study was consecutively conducted in a comprehensive tertiary hospital in Foshan city of Guangdong Province, China, from August 1, 2019, to November 30, 2019. Blood lead levels were measured in maternal whole blood in 12-27 (+6) weeks of pregnancy, using atomic absorption spectrometer. Preeclampsia diagnosis was ascertained from the electronic medical records system. The risk of preeclampsia was estimated by multivariable logical regression analysis, and a two-stage linear regression model was established to find out the dose-effect.

RESULTS

A total of 2174 people were included in this study, and 59 (2.7%) women developed preeclampsia. The dose-effect analysis revealed a non-linear association between blood lead levels and the risk of preeclampsia, with a cut-off point at 4.2 μg/dl. When blood lead levels were over 4.2 μg/dl, the risk of preeclampsia increased significantly with an increase in blood lead levels (OR = 2.05, 95%CI: 1.50, 2.81). In the multivariate regression models, per 1 μg/dl increment in blood lead levels was associated with 43% higher risk of developing preeclampsia (OR = 1.43,95%CI:1.17,1.74). Moreover, the association between blood lead levels and preeclampsia was stable in different subgroups.

CONCLUSIONS

Low levels of lead exposure had a dose-effect relationship of preeclampsia, with a cut-off point at 4.2 μg/dl. Blood lead levels had a non-linear association with preeclampsia. When the blood lead levels were higher than 4.2 μg/dl, the risk of preeclampsia increases by 105% for every 1 μg/dl increase in blood lead levels.

Biomonitoring of Lead Exposure in Children from Two Fishing Communities at Northern Colombia

Lead (Pb) exposure is a growing concern in developing countries, especially in vulnerable children. The objective of this study was to evaluate blood lead levels (BLL) in children from two fishing populations at Northern Colombia, Loma de Arena and Tierrabomba, as well as their association with morphometric parameters, markers of hematological status, liver function, and mRNA expression of genes related to Pb toxicity. A total of 198 blood samples were collected from participants aged 5-16 years old. The mean (± standard error) BLL for the studied sample was 3.6 ± 0.3 μg/dL, and the 97.5th percentile was 21.0 μg/dL. The participants of Loma de Arena and Tierrabomba presented BLL of 3.9 ± 0.5 and 2.9 ± 0.3 μg/dL, respectively. Children born preterm had greater BLL than those born at full term. Boys had greater BLL than girls, which also occurred for participants between 12 and 16 years old, compared with those aged 5-11 years old. The BLL were negatively correlated with body mass index in children from Loma de Arena, but an opposite behavior was observed for Tierrabomba. In Loma de Arena, the mRNA expression of interferon gamma, a pro-inflammatory cytokine, increased with the BLL, but that of δ-aminolevulinic acid dehydrogenase, a sensor for Pb poisoning, decreased. In Tierrabomba, gene expression did not change with BLL. These results show that in fishing communities, lead exposure promotes different health impacts depending on age, sex, and other site-specific factors. In any case, appropriate educational and intervention programs should be carried out to minimize Pb exposure in children.

Retrospective blood lead assessment from archived clotted erythrocyte fraction in a cohort of lead-exposed mother-child dyads

Exposure to lead (Pb) is linked to a host of adverse health effects. Recent revelations of unmonitored exposures to hazardous levels of lead as seen in the Flint Water Crisis have manifested a need for evaluating biological samples, other than regularly prepared whole blood, for biomonitoring of lead exposure. Here, we present a method utilizing clotted erythrocyte fraction samples, which are commonly archived along with serum (or plasma) in biorepositories, to predict whole blood lead levels to allow for retrospective assessments of environmental exposure to lead. Whole blood and clotted erythrocyte fraction samples were collected from 91 participants in the Airborne Exposure to Semivolatile Organic Pollutants (AESOP) cohort study of mother-child dyads. Clotted erythrocyte fraction samples were prepared either using microwave assisted acid digestion or alkaline dilution and subsequently analyzed for lead using Inductively-couple plasma-mass spectrometry (ICP-MS). Simultaneously withdrawn whole blood samples were also analyzed. A strong linear relationship was observed between lead in whole blood and clotted erythrocyte fraction with Pearson correlation coefficients (r) of 0.90, and 0.89 (p < 0.001) for acid digestion and alkaline dilution, respectively. Slopes and intercepts from simple linear regression models of the two clotted erythrocyte fraction methods were not found to be significantly different (p > 0.05) when compared to the standard blood lead assay method. Modeled blood lead predicted from clotted erythrocyte fraction was evaluated at a test threshold of 3 μg/dL was found to have diagnostic sensitivity of 88% and specificity of 100%. Results from this study demonstrate clotted erythrocyte fraction samples are a viable alternative biological sample for retrospective public health surveillance of environmental exposure to lead.

The lead story of the fire at the Notre-Dame cathedral of Paris

On 15th April 2019, Parisians watched in shock as Notre-Dame de Paris, the iconic cathedral that has towered over their city for almost 900 years, was engulfed in flames. Although flames destroyed the spire and considerably weakened the structure, no human lives were lost. However, as some amounts of lead volatilized and deposited in the surrounding areas, fears of potential intoxication began to rise. We investigated the impact of this fire on the blood lead levels of adults in Paris according to the distance between the cathedral and where they live or work. The geometric mean of blood lead levels of the study population was 1.49μg/dl (95% CI [1.38-1.62]) with a prevalence of blood lead levels≥5.0μg/dL of 5.0%. Despite the early legitimate fears of intoxication, the fire that destroyed a significant part of the Notre-Dame cathedral did not increase the blood lead levels of adults living and working in the vicinity.

Exploring persistent racial/ethnic disparities in lead exposure among American children aged 1-5 years: results from NHANES 1999-2016

OBJECTIVE

The aim of this study was to determine whether long-standing racial disparities in lead exposure still exists for children age 1-5 years old. We examined if blood lead levels were higher among non-Hispanic Black children and others compared to non-Hispanic White children.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) from 1999-2016 were used. Geometric mean blood lead levels (BLLs) were compared by race/ethnicity using log-transformed simple linear regression. Associations between race and elevated BLL were assessed using weighted Chi-square tests. Log-transformed multiple weighted linear regression was used to assess what factors affected BLLs.

RESULTS

A total of 6772 children were included in this study. In 1999-2000, the geometric mean BLL for non-Hispanic Black children was 3.08 μg/dL, compared to 2.03 μg/dL for non-Hispanic White children (p = 0.01). The difference in geometric mean BLL between non-Hispanic Black children and non-Hispanic White children continued to be statistically significant in later years (all p < 0.05) until 2015-2016 (0.89 μg/dL vs 0.74 μg/dL, p = 0.17). Log-transformed linear regression showed that being non-Hispanic Black and having low family income were independently associated with higher BLL.

CONCLUSION

Although lead exposure in the general population continued to decline for all racial/ethnic groups, non-Hispanic Black children still had higher BLL than non-Hispanic White children. In more recent years, the racial/ethnic gap was lesser but persisted. Racial/ethnic disparity in childhood BLL could be partially explained by socio-economic factors.

Snack foods and lead ingestion risks for school aged children: A comparative evaluation of potentially toxic metals and children's exposure response of blood lead, copper and zinc levels

Snack foods are common and highly advertised to children and serve their natural predispositions for sweet and salty tastes. However, the risk issues of low-cost snacks eaten by 0-6 aged children are lack of more concern. To better understand the issue of low-cost snacks this study considered potentially toxic metals (PTMs) impact on children's health risk, measured PTMs in a collection of 570 collected low-cost snacks contributed by 1342 voluntary participants children aged 0-6 years involved in Xi'an city are conducted. Nine priority PTMs and amounts ranked as Mn > Zn > Cu > Cr > Sb > Pb > Ni > Cd > Co. The Estimated Weekly Intake of PTMs in snacks for children accounted for a proportion of the Provisional Tolerance Weekly Intake. Children's daily snack ingestion of Cr, Cd and Pb were especially concerning. It was noted that all PTMs in flour products contribute to the total Target Hazard Quotient (THQ>1) were observed having a non-carcinogenic risk compared to the single metals Cr, Co and Cd with carcinogenic risk. The correlations between Cu, Pb, Zn in low-cost snacks and children's bloods reflected PTMs especially for Pb that transfers into children's bodies mostly through low-cost foodstuffs ingestion. Also, the elevated blood lead levels (BLLs) depended on readily available, low-quality snacks accessible for children. Therefore, multi-initiatives aimed at improving the quality, increasing awareness, and a PTM monitoring program for low-cost snack food market to young children should be undertaken.

Lead exposure induces metabolic reprogramming in rat models

Lead is a toxin of great public health concern affecting the young and aging population. Several factors such as age, gender, lifestyle, dose, and genetic makeup result in interindividual variations to lead toxicity mainly due to variations in metabolic consequences. Hence, the present study aimed to examine dose-dependent lead-induced systemic changes in metabolism using rat model by administering specific doses of lead such as 10 (low lead; L-Pb), 50 (moderate lead; M-Pb), and 100 mg/kg (high lead; H-Pb) body weight for a period of one month. Biochemical and haematological analysis revealed that H-Pb was associated with low body weight and feed efficiency, low total protein levels (p ≤ 0.05), high blood lead (Pb-B) levels (p ≤ 0.001), low ALAD (δ-aminolevulinate dehydratase) activity (p ≤ 0.0001), high creatinine (p ≤ 0.0001) and blood urea nitrogen (BUN) (p ≤ 0.01) levels, elevated RBC and WBC counts, reduced haemoglobin and blood cell indices compared to control. Spatial learning and memory test revealed that H-Pb exposed animals presented high latency to the target quadrant and escape platform compared to other groups indicating H-Pb alters cognition function in rats. Histopathological changes were observed in liver and kidney as they are the main target organs of lead toxicity. LC-MS analysis further revealed that Butyryl-L-carnitine (p ≤ 0.01) and Ganglioside GD2 (d18:0/20:0) (p ≤ 0.05) levels were significantly reduced in H-Pb group compared to all groups. Further, pathway enrichment analysis revealed abundance and significantly modulated metabolites associated with oxidative stress pathways. The present study is the first in vivo model of dose-dependent lead exposure for serum metabolite profiling.

Influence of task-based airborne lead exposures on blood lead levels: a case study of informal automobile repair artisans in Nakuru town, Kenya

Lead poisoning is an emerging worldwide public health concern, especially in the developing countries. Occupational tasks such as spray painting and welding in informal automobile repair enterprises present risks of exposures to lead generally through inhalation and ingestion. The artisans therefore risk high blood lead (BPb) levels, which is critical to chronic adverse health effects of lead. The study aimed at assessing the influence of occupational tasks on personal airborne lead exposures and to evaluate the association between these exposures with blood lead (BPb) levels among the artisans. A cross-sectional study was conducted in ten informal automobile repair workshops. Task-specific personal inhalable air samples and blood samples were collected concurrently for 20 participants performing five distinct occupational tasks. Lead levels were analysed using inductively coupled plasma atomic emission spectroscopy and data analysed by analysis of variance, simple and multiple linear regressions. The results indicated significant differences in airborne lead (PbA) exposure levels in different occupational tasks (p = 0.000). Lead-acid battery repairs recorded mean PbA exposure level of [76.11 ± (10.81 SE) µg/m³] exceeding the WHO 50 µg/m³ airborne lead permissible exposure limit. The average (PbA) exposure level was 22.55 ± (5.05 SE) µg/m³, while the mean (BPb) level was 25.08 ± (3.48 SE) µg/dl. A significant positive correlation between task-based airborne lead with blood lead levels was observed (r = 0.68, p = 0.001). In conclusion, the occupational tasks influenced personal airborne lead exposure levels, which in turn was an important predictor of blood lead levels. The study recommends lead exposure assessments, medical screening and intervention measures to minimize the risk and consequences of occupational exposures to lead among the study population.

Association of Blood Lead Levels with the Risk of Depressive Symptoms in the Elderly Chinese Population: Baseline Data of a Cohort Study

Previous studies have reported an association between blood lead (BPb) levels and depressive symptoms in adults. However, the relationship between BPb levels and depression remains unclear in the old population. Our purpose was to investigate the association of BPb levels with depression among the old population. Data were gathered from 994 elderly persons in the Cohort Study of Elderly Health and Environmental Controllable Factors, which was created in Anhui, China. BPb was measured by inductively coupled plasma mass spectrometry. Our subjects were divided into four groups according to BPb quartiles. Multivariate logistic regressions were used to assess the association between BPb levels and depression. The median (25th-75th) BPb level was 26.94 μg/L (20.34 μg/L-36.13 μg/L). BPb levels in participants with depression were higher than those in participants without depression. The prevalence of depression was 27.64%. After multivariate adjustment for confounding factors, participants with BPb level in the highest quartile had 2.03 times higher risk of depression compared with those in the lowest quartile. In rural areas, the risk of depression in higher BPb quartile was higher than that in the lowest quartile. These findings suggest that higher BPb level was associated with increased odds of depression in the old population. This association was obvious among older people living in rural areas.

Superfund Cleanups and Children's Lead Exposure

This study evaluates the effect of EPA's Superfund cleanup program on children's lead exposure. We linked two decades of blood lead level (BLL) measurements from children in six states with data on Superfund sites and other lead risk factors. We used quasi-experimental methods to identify the causal effect of proximity to Superfund cleanups on rates of elevated BLL. We estimated a difference-in-difference model comparing the change in elevated BLL of children closer to versus farther from lead-contaminated sites before, during, and after cleanup. We also estimated a triple difference model including children near hazardous sites with minimal to no lead contamination as a comparison group. We used spatial fixed effects and matching to minimize potential bias from unobserved differences between the treatment and comparison groups. Results indicate that Superfund cleanups lowered the risk of elevated BLL for children living within 2 kilometers of lead-contaminated sites 13 to 26 percent.

Blood lead levels among Chinese children: The shifting influence of industry, traffic, and e-waste over three decades

In China, data relating to the historic prevalence of childhood lead poisoning suggest its pervasiveness. This review analysed published epidemiological data on blood lead levels (BLLs) of 735,271 Chinese children aged 0-6 between 1987 and 2017. Among these children, the geometric mean (GM) BLL was 95.1 μg/L (geometric SD = 1.62), and 24.1% suffered lead poisoning (BLL ≥ 100 μg/L). Importantly, there was a temporal decrease in the GM BLL value, from 182.9 μg/L in 1987-1991 to 42.4 μg/L in 2012-2017. However, a rebound was seen in the most recent two years (2016 and 2017). Moreover, the GM BLL among Chinese children has not fallen as low as U.S. children. This indicates that either (1) leaded petrol or lead based-paint exposure sources have not been adequately controlled in China, or (2) other pollution sources, such as industry, traffic, and e-waste, are impacting Chinese children. Drivers behind spatio-temporal variations were explored to provide scientific evidence regarding the prevention of childhood lead poisoning. We found that BLLs among children in the central and eastern areas of China have dropped lower than those in the western area, and that the GM BLL of children living in rural areas now exceeds children in urban areas. These reversals may be associated with the industrial decentralization policy of the late 1980s, when many heavily polluting industries and manufacturers moved away from cities on the east coast. It was discovered that the BLLs of children living in areas associated with mining have remained high (GM BLL = 155.0 μg/L for 2007-2017), and that the lead poisoning rate (LPR) has become exceptionally high in areas associated with e-waste. Finally, the review offers a data comparison with other countries, an overview of potentially influencing factors and sources, as well as some suggested prevention strategies to reduce childhood lead exposure.

Blood Lead Levels in Occupationally Exposed Workers Involved in Battery Factories of Delhi-NCR Region: Effect on Vitamin D and Calcium Metabolism

Workers involved in battery manufacturing or recycling factories are occupationally exposed to high concentrations of lead. In humans, lead can cause a wide range of biological effects depending upon the level and duration of exposure. The purpose of this study was to find out the blood lead levels (BLL) in occupationally exposed workers involved in battery industry in Delhi NCR region and to study whether lead affected the vitamin D (vit D) and calcium metabolism. For this study 100 occupationally lead-exposed battery workers (LEBW) and 100 non-lead exposed controls (NLEC) were recruited. BLL were measured using inductively coupled plasma optical emission spectrometer (ICP-OES) technique while ELISA was performed to quantify the serum vit D levels in the study subjects. Routine biochemical parameters were measured by chemistry autoanalyzers. Statistical analysis was done using appropriate statistical tools. Results showed that BLL were significantly higher in LEBW as compared to NLEC (p < 0.0001). Serum vitamin D, calcium and phosphorus levels were significantly decreased in battery workers as compared to controls (p < 0.005). Spearman's rank correlation analysis showed significant negative correlation of BLL with serum Vitamin D and calcium levels. Significant positive correlation was observed between BLL and duration of lead exposure. Weak negative correlation was also observed between BLL and vit D even after adjusting for smoking status. In conclusion, this study demonstrated that higher BLL significantly alters the vit D and calcium metabolism.

Association of Musculoskeletal Disorders and Inflammation Markers in Workers Exposed to Lead (Pb) from Pb-battery Manufacturing plant

Background:

Lead (Pb) deposits in the skeletal system on chronic exposure and releases to circulation over a period. The musculoskeletal disorders (MSDs) are associated with enhanced expression of inflammation. The combination of Pb-exposure and MSDs induced inflammation was not attempted.

Objective:

This study was conducted to examine the association between MSDs and inflammatory markers in workers exposed to Pb from Pb-battery plant.

Material and Methods:

In a case-control study design, the study enrolled 176 male Pb-exposed workers as study subjects and 80 healthy workers with no occupational exposure to Pb as control subjects. The Nordic musculoskeletal questionnaire was used to assess the MSDs. From the blood sample, blood lead level (BLL) and High Sensitivity C-reactive protein (Hs-CRP) were estimated as markers of Pb-exposure and Inflammatory marker respectively. The BLL was estimated by flame atomic absorption spectrometric method and the Hs-CRP by using a diagnostic kit method.

Results:

Significantly high proportions of MSDs were noted in study subjects as compared to controls. The MSDs identified in the study subjects were at low back (33%) followed by knee (26%), shoulders (16%), neck (14%), ankle/foot (11%), wrist/hand (10%), elbows (8%), upper back (7%), and hips/thighs (5%). The significant association between Pb-exposure and MSDs among study subjects was mainly noted in low back and ankle/foot. Also, significantly high serum Hs-CRP levels were noted among study subjects with ankle/foot MSDs.

Conclusion:

Pb-exposure and inflammatory markers were significantly associated with lower limbs of MSDs.

Association of low-level blood lead with serum uric acid in U.S. adolescents: a cross-sectional study

BACKGROUND

Uncertainty remains regarding the association between blood lead levels (BLL) and serum uric acid (SUA) with relatively low BLL exposure because of limited data in the adolescent population. We examined the association between BLL and SUA in U.S. adolescents.

METHODS

In this cross-sectional study, 8303 adolescents aged 12-19 years from NHANES 1999-2006 were analyzed. BLL was Ln-transformed for analysis for the skewed distribution. Elevated SUA was defined as ≥5.5 mg/dL. Multivariate linear and multiple logistic regression analyses were performed to evaluate the association of BLL with SUA and elevated SUA. Moreover, a generalized additive model (GAM) and a fitted smoothing curve (penalized spline method) were conducted.

RESULTS

The overall mean BLL was 1.3 μg/dL. Multivariate linear regression analyses showed that LnBLL was independently and positively correlated with SUA level (β = 0.13, 95%CI: 0.09-0.17). Multiple logistic analyses showed that LnBLL was associated with a 24% increased prevalence of elevated SUA (OR = 1.24; 95% CI, 1.11-1.38). Analyses using restricted cubic spline confirmed that the associations of LnBLL with SUA and elevated SUA were linear. Subgroup analyses showed that stronger associations between LnBLL and SUA were detected in adolescents with lower levels of education and estimated glomerular filtration rate (eGFR) (all P for interaction < 0.05).

CONCLUSIONS

BLL was independently and positively correlated with SUA level and elevated SUA among U.S. adolescents, particularly with lower levels of education and eGFR. The data suggest that there is no "safe" threshold level of exposure to lead.

Lead release to potable water during the Flint, Michigan water crisis as revealed by routine biosolids monitoring data

Routine biosolids monitoring data provides an independent and comprehensive means to estimate water lead release pre-, during and post-Flint Water Crisis (FWC). The mass of potable plumbing-related metals (i.e., lead, cadmium, copper, nickel and zinc) in sewage biosolids strongly correlated with one another during the FWC (p < 0.05). A simple parametric regression model based on 90^th percentile potable water lead measurements (WLL90) from five city-wide citizen science sampling efforts August 2015-August 2017 was strongly correlated to corresponding monthly lead mass in biosolids [Biosolids-Pb (kg) = 0.483 x WLL90 (μg/L) + 1.79; R² = 0.86, p < 0.05]. Although total biosolids lead increased just 14% during the 18 months of the FWC versus the comparable time pre-FWC, 76% of that increase occurred in July-September 2014, and the corresponding percentage of Flint children under 6 years with elevated blood lead ≥ 5 μg/dL (i.e., %EBL5) doubling from 3.45% to 6.61% in those same three months versus 2013 (p < 0.05). %EBL5 was not statistically higher during the remaining months of the FWC compared to pre-FWC or post-FWC. As expected, lead in biosolids during the FWC, when orthophosphate was not added, was moderately correlated with water temperature (R² = 0.30, p < 0.05), but not at other times pre- and post-FWC when orthophosphate was present. Tripling the orthophosphate dose post-FWC versus pre-FWC and some lead pipe removal, decreased lead in biosolids (and %EBL5) to historic lows (2016-2017 vs. 2012-2013; p < 0.05), supporting the effectiveness of these public health interventions in reducing childhood water lead exposure.

Lead toxicity with a new focus: Addressing low-level lead exposure in Canadian children

Although acute and subacute lead toxicity requiring active treatment is rare in Canada, paediatricians need to be aware of new evidence linking lower lead levels to neurodevelopmental deficits. Health Canada has identified potential exposures occurring prenatally, in infancy and during early childhood from food and water, household dust, soil, and mouthing products that contain lead. Children with neurodevelopmental problems who live in older housing and newcomers to Canada may be at greater risk. Symptoms may be latent, subtle, and chronic. Blood assay, widely available clinically, does not confirm diagnosis unless lead exposure has been recent. Human biomonitoring data are available in the Canadian Health Measures Survey, and Health Canada has suggested that clinicians use these new reference ranges. Early detection and prevention of lead exposure are key public health objectives because effects of lead toxicity are chronic and treatment is complex.

Cost-benefit of point-of-use devices for lead reduction

BACKGROUND

Lead exposure represents a significant human health concern that often occurs with little warning to the consumer. Water lead levels can be mitigated by point-of-use (POU) devices such as reverse osmosis, distillation, or activated carbon with lead reduction media.

OBJECTIVES

This study assessed a partial cost-benefit of residential installation of POU devices to reduce lead concentrations in drinking water and examined the economic impact at the community level based on exposures reported in Flint, Michigan.

METHODS

We calculated the individual consumer breakeven point for each lead abatement option by subtracting the lifetime cost of device installation and maintenance from the lifetime cost of lead exposure through its impact on intelligence (IQ) and lifetime earnings. This approach was then extrapolated to the community level based on reported lead exposures in Flint, Michigan.

RESULTS

Based on operating POU device costs, lead absorption from water, and economic losses associated with reduced IQ, initial water lead levels associated with consumer breakeven points for reverse osmosis (7.31 µg/L), activated carbon (3.73 µg/L), and distillation (12.0 µg/L) were calculated. For example, an individual consuming water with 25 µg/L of lead, similar to the 90th percentile of concentrations measured in Flint, Michigan, would have an expected blood lead level of 1.25 µg/dL, a corresponding loss of 0.641 IQ points, and a lifetime economic earnings loss of $14,284. Over 70 years of continued use, activated carbon with lead reduction media is the least expensive device to maintain and operate as compared to reverse osmosis and distillation.

CONCLUSIONS

Infrastructure failures related to drinking water are unpredictable and exposure to contaminates can have significant economic ramifications. POU devices represent a cost-effective option to reduce the impact of lead exposure, particularly when water lead concentrations exceed regulated levels.

The CDC blood lead reference value for children: time for a change

The purpose of this article is to consider alternate uses of the blood lead reference value for children. There are two possible approaches. Historically the reference value has been used to guide clinical and public interventions for individual children. As the distribution of blood lead levels in the population has been lowered over time, the blood lead level at which interventions are recommended has also been reduced. The use of a reference value of 3.5 μg/dL, based on the 98 percentile of blood lead levels for children in 2011-2014 National Health and Nutrition Examination Survey is under review. For several reasons, adopting the new reference value to guide clinical and public health management puts practitioners in an untenable position. First, the changes in the brain caused by lead are significant and persistent. However, these adverse impacts are subtle and although clearly identified at the population level, not predictive for individual children. In addition, the recommended interventions have not been shown to reduce blood lead levels once they are elevated. Finally, clinical laboratory and office-based blood lead testing devices are not required to quantify blood lead levels < 4 μg/dL and in many cases cannot reliably test for low blood lead levels. Revising the reference value also will undoubtedly result in diversion of resources away from those population-based interventions which have demonstrated success. We argue for second approach, in the management of lead poisoning in the US from one of evaluation and management at the individual level to one of population based primary prevention. This would require a strategy directed at controlling or eliminating lead in children's environment before they are exposed. The reference value, as a benchmark, is essential to ensure that primary prevention efforts are successful.

Spatial distribution of lead contamination in soil and equipment dust at children's playgrounds in Beijing, China

Lead contamination is widespread across China, posing a serious public health concern. In quantifying child lead exposure, established health risk assessment (HRA) approaches often take into account residential soil lead levels. However, this may not constitute a significant exposure source for children in urban mainland China, where the population mainly dwell in high-rise buildings without back or front yards. In this setting, children's playgrounds may represent a more probable exposure source. The present study analyzed lead levels in settled dust on playground equipment and in surficial soils at 71 playgrounds in Beijing, China. Our results reveal that the average playground dust lead concentration was 80.5 mg/kg, more than twice the average soil lead concentration of 36.2 mg/kg. It was found that there are differences in statistical and spatial distributions for lead in playground dust and soils. Lead levels in equipment dust were largely consistent across Beijing, with elevated levels detected at locations in the main city area, the newly developed Tongzhou District, and the rural counties. Whereas average soil lead concentrations were higher at playgrounds in the main city area than other areas of Beijing. Statistical analysis suggests that the lead content in dust and soil may derive from different natural and anthropogenic sources. Equipment dust lead may be associated with long-distance atmospheric transportation and deposition. Whereas lead in soil is more likely to be associated with local traffic. This study also found that, in certain areas of Beijing, the risk of blood lead levels (BLLs) exceeding safe levels was up to 6 times higher when based on dust exposure than when based on playground soil exposure. The results of this study suggests that HRA undertaken for children in urban mainland China should pay closer attention to children's playgrounds as a lead exposure source, and, in particular, playground equipment dust.

Environmental and socioeconomic factors induced blood lead in children: an investigation from Kashmir, India

Blood lead toxicity has been prominently related to vehicular emissions. The lead is a carcinogenic metal systematically damages bones and central nervous system. The present investigation is focused on likely impacts of environmental and socioeconomic factors on the concentration of blood lead levels in children. The findings of the study show that the highest blood lead levels were observed in the age group of 4-8 years (5.46 μg/dl) with mother's education having an inverse proportionality with the blood lead levels of children. Furthermore, children belonging to families with income (> 100,000) exhibited the highest blood lead levels (5.52 μg/dl) than the rest of the categories which was further advocated by lower blood lead levels in children residing in better residential conditions. High proximity of school to highway distance seemed to play a vital role in the concentration of lead in children while the traffic flow density was observed to have proportionality effect on the blood lead levels. From the study, it is concluded that 28% of the children in the sample population were having lead levels above the permissible limits as per Centre for Disease Control and Prevention. The study reflects the alarming toxicity of lead in children residing in a non-industrial region which further gives rise to concerns about the health of the children residing in industrialized regions of the world with high lead levels in the environment.

Lead exposure from households and school settings: influence of diet on blood lead levels

Lead is known as a potent toxicant to human health, particularly for children while their central nervous system is developing. The aim of this study was to investigate the associations between blood lead levels (BLLs) and lead exposure in the children's diet, home, and school environments. A cross-sectional study was conducted with 153 children aged 1-4 years, in four day care centers (DCCs), where a high prevalence of lead exposure was previously found. Lead determination by graphite furnace atomic absorption spectrometry (GF-AAS) was performed for venous blood, drinking water collected in the DCCs, and the 24-h diet (n = 64). Environmental screenings were conducted to evaluate lead concentrations in the tableware, buildings, and playground items in all DCCs and children's homes (n = 18) by using a field-portable X-ray fluorescence analyzer (FP-XRF). The BLL mean was 2.71 μg dL^-1. Means for 24-h lead concentrations in the diet were 1.61 and 2.24 μg kg^-1 of body weight (BW) in two DCCs. Lead concentrations in the water supply were lower than 2 μg L^-1. More than 11% of the DCCs' environmental analyses presented lead concentrations higher than or equal to 1 mg cm^-2, as defined by the USEPA. The diet was not found to be a risk factor for lead exposure, but households and DCC settings raised concern. Children's exposure to lead in DCC environments, where they spend the most part of their weekdays, appeared to be relevant. Graphical abstract ᅟ.

Cost-benefit analysis for a lead wheel weight phase-out in Canada

Lead wheel weights (LWWs) have been banned in Europe, and some US States, but they continue to dominate the market in Canada. Exposure to lead is associated with numerous health impacts and can result in multiple and irreversible health problems which include cognitive impairment when exposure occurs during early development. Such impacts incur high individual and social costs. The purpose of this study was to assess the costs and public health benefits of a Risk Management Strategy (RMS) that would result from a LWW phase-out in Canada and compare this to a Business-As-Usual (BAU) scenario. The contribution of LWWs to lead concentrations in media including roadway soil/dust, ambient and indoor air, and indoor dust were estimated. The Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK) was used to develop estimates for the blood lead levels (BLLs) in children (μg/dL) associated with the BAU and the RMS. The BLLs estimated via the IEUBK model were then used to assess the IQ decrements associated with the BAU that would be avoided under the RMS. The subsequent overall societal benefits in terms of increased lifetime earning potential and reduced crime rate, were then estimated and compared to industry and government costs. LWWs form 72% of the Canadian wheel weight market and >1500 tonnes of lead as new LWWs attached to vehicles enters Canadian society annually. We estimate that 110-131 tonnes of lead in detached WWs are abraded on roadways in Canada each year. A LWW phase-out was predicted to result in a drop in pre-school BLLs of up to 0.4 μg/dL. The estimated net benefits associated with the RMS based on cognitive decrements avoided and hence increased lifetime earning potential (increased productivity) and reduced crime are expected to be: C$248 million (8% discount rate) to C$1.2 billion (3% discount rate) per year.

Lead-based paint in children's toys sold on China's major online shopping platforms

Lead in paint is a major public health concern and has drawn much attention from international organizations such as the World Health Organization (WHO) and the United Nations Environmental Programme (UNEP). However, there is limited research on lead-based paint, especially its use in toys, which poses an explicit health risk to vulnerable children. The present study sampled 100 different toys purchased from the three largest online shopping platforms in China: JD, Taobao (TB) and Tmall (TM). These selected toys have been sold nearly 3 million times in total, suggesting that they may have reached the dwellings of millions of children. It was found that the toys sold by JD and TM, which are considered organized sellers, had average lead concentrations of 25 mg/kg and 32 mg/kg, respectively, much lower than that of toys sold by unorganized sellers on the TB platform, at 219 mg/kg. Approximately 12% of the toys purchased from TB contained paint with total lead concentrations exceeding China's regulatory standard for paints in toy manufacturing, and nearly 36% of the toys purchased from TB exceeded the equivalent US regulatory standard and EU standard. These results suggest that further action is needed to verify the health and safety standards of toys sold by such unorganized sellers. Moreover, this study found that China's regulatory standard (90 mg/kg) based on soluble lead may underestimate the risk posed by lead in paints, and it is suggested that future regulatory thresholds for lead levels in paints for toy manufacture be based on total rather than soluble lead concentrations. The present study also explored various influencing factors on lead concentration, and found that lead concentrations were related to toy price, age group, color, and sales volume.

Blood lead and cadmium levels in preschool children and associated risk factors in São Paulo, Brazil

In Brazil, there are scarce data on lead (Pb) and cadmium (Cd) contamination, especially for more vulnerable populations such as preschool children. In this paper, we answer two questions: (1) What are the exposure levels of lead and cadmium in preschool children, in Sao Paulo, Brazil? and (2) What are the risk factors associated with this exposure? This cross-sectional study included 50 day care centers (DCCs), totaling 2463 children aged 1-4 years. Venous blood samples were analyzed by ICP-MS. Questionnaires were administered to the parents. Multiple logistic regression models were used to identify associations between blood lead levels (BLLs) and blood cadmium levels (BCLs) and potential risk factors. The geometric mean for BLLs was 2.16 μg/dL (95% CI: 2.10-2.22 μg/dL), and the 97.5th percentile was 13.9 μg/dL (95% CI: 10.0-17.3 μg/dL). For cadmium exposure, the geometric mean for BCLs was 0.48 μg/L (95% CI: 0.47-0.50 μg/L), and the 95th percentile was 2.57 μg/L (95% CI: 2.26-2.75 μg/L). The DCCs' geographic region was associated with high BLLs and BCLs, indicating hot spots for lead and cadmium exposures. In addition, it was found that the higher the vehicles flow, the higher were the BLLs in children. Red lead in household gates was also an important risk factor for lead exposure. Comparing these results with the findings of the Fourth National Report on Human Exposure to Environmental Chemicals by CDC-2013, it was found that in Brazilian preschool children the BLLs are almost three times higher (97.5th percentile) and the BCLs are almost twelve times higher (95th percentile) than those in U.S. children. This information is essential to formulate public health policies.

Assessment of lead exposure among automobile technicians in Khyber Pakhtunkhwa, Pakistan

Exposure to Pb among automobile technicians in selected towns of Khyber Pakhtunkhwa Province, Pakistan, was studied using a questionnaire, biological sampling (blood, hair, nails), and analysis of Pb biomonitoring data across various subgroups of occupation, age, and years of exposure. The study population included exposed automobile technicians (n=50) and a control group (n=50). The automobile technicians were further stratified into 4 groups: mechanics, auto-body technicians, electricians, and painters. Mean Pb levels in biological samples of the automobile technicians were significantly higher than in the control group (P<0.01). The Pb concentrations (mean±standard deviation) in whole blood, hair, and nails of automobile technicians were 65.3±41.9μgdL^-1, 23.6±11.2mgkg^-1 and 29.7±14.5mgkg^-1, respectively, whereas concentrations in the control group were 21.7±17.6μgdL^-1, 4.8±3.4mgkg^-1 and 7.2±3.9mgkg^-1. Fifty two percent of the automobile technicians had blood levels >50μgdL^-1, but only 14% of the control group exceeded this level. Considering that Pb blood levels of 50μgdL^-1 exceed maximum concentrations recommended by leading public health organizations, appropriate measures should be taken to protect the welfare of the exposed automobile technicians and their families.

Low levels of lead and glutathione markers of redox status in human blood

Exposure to lead (Pb) is implicated in a plethora of health threats in both adults and children. Increased exposure levels are associated with oxidative stress in the blood of workers exposed at occupational levels. However, it is not known whether lower Pb exposure levels are related to a shift toward a more oxidized state. To assess the association between blood lead level (BLL) and glutathione (GSH) redox biomarkers in a population of healthy adults, BLL and four GSH markers (GSH, GSSG, GSH/GSSG ratio and redox potential E h ) were measured in the blood of a cross-sectional cohort of 282 avid seafood-eating healthy adults living on Long Island (NY). Additionally, blood levels of two other metals known to affect GSH redox status, selenium (Se) and mercury (Hg), and omega-3 index were tested for effect modification. Regression models were further adjusted for demographic and smoking status. Increasing exposure to Pb, measured in blood, was not associated with GSSG, but was associated with lower levels of GSH/GSSG ratio and more positive GSH redox potential E h , driven by its association with GSH. No effect modification was observed in analyses stratified by Hg, Se, omega-3 index, sex, age, or smoking. Blood Pb is associated with lower levels of GSH and the GSH/GSSG ratio in this cross-sectional study of healthy adults.

Resurgent lead poisoning and renewed public attention towards environmental social justice issues: A review of current efforts and call to revitalize primary and secondary lead poisoning prevention for pregnant women, lactating mothers, and children within the U.S

The recent Colorado Gold King Mine waste-water spill and Michigan's water supply re-routing program catastrophe, has directed renewed public attention towards resurgent environmental lead contamination threats. Leaded environments present social justice issues for children and mothers possessing blood lead levels (BLLs) > 5 μg/dL. Childhood lead exposure remains a continual U.S. public health problem manifesting in lifelong adverse neuropsychological consequences. The 2007 Inspector General Report demonstrated low BLL screening rates across the U.S. and this study examined the regularity of children's BLL screening rates. The Centers for Disease Control and Prevention (CDC) Lead Poisoning National Surveillance 2010-2014 children's BLL screening rates, were examined to assess BLL screening regularity in states traditionally known to have regularly occurring BLL screenings: New York, New Jersey, and Pennsylvania. The results extracted from the CDC data showed that < 50% of children were BLL screened by six-years of age across the states that were sampled. The findings highlight that without a "clear map" of lead exposed areas through accurate and consistent BLL screenings, how the potential for such disparities within - and between-states within the U.S. could arise due to environmental social justice issues in relation to BLL screening barriers. Barriers preventing children's BLL screenings were considered, and public health interventions recommended to improve screening rates included: routine BLL screening for all pregnant women, lactating mothers, and children; while, removing known lead exposure sources within communities. This study calls for action during a time of renewed public attention to resurgent lead poisoning within the U.S.

Blood lead levels of children in urban and suburban areas in China (1997-2015): Temporal and spatial variations and influencing factors

Blood lead (Pb) poisoning is a worldwide heath problem, especially in developing countries. As the largest developing country in the world, China faces severe health challenges, in particular the threat of blood Pb poisoning. In this study, the temporal trend of Chinese children's blood lead levels (BLLs) and blood lead poisoning incidence (BLPI) (percentage of BLL>100μg/L) and its influencing factors were investigated. We collected articles on children's BLLs published from 1997 to 2017 with sampling time from 1997 to 2015 by searching the databases of VIP Medical Information System (VMIS), China National Knowledge Infrastructure (CNKI) and Wanfang Data. After a rigorous investigation, 259 articles with eligible inclusion criteria were reviewed. Meanwhile, the data of Pb concentrations in the soil of 23 cities and the annual mean PM10 (particulate matter<10μm) concentrations of 24 provincial cities were collected. The temporal trend of children's BLLs and BLPIs could be divided into three stages: upward trend from 1997 to 2000, downward trend from 2001 to 2013, and upward trend from 2014 to 2015. The decline of BLLs from 2001 was primarily due to the phasing out of leaded gasoline since 2000 in China, while the descending air quality could explain the upward trend of BLLs in the period from 2014 to 2015. The correlation and regression analysis indicated that soil and air were two major pathways of Pb exposure for children in China. Although a noticeable decrease has been shown, the Chinese children's BLLs were still significantly higher than the levels of developed countries. We highly recommended that the critical value of blood Pb poisoning should be lowered to 50μg/L in China. Guidelines on the prevention and management of blood Pb poisoning are needed in China.

Connecting gastrointestinal cancer risk to cadmium and lead exposure in the Chaoshan population of Southeast China

Cadmium (Cd) and lead (Pb) pose a serious threat to human health because of its carcinogenicity. China ranks first according to the Global Cancer Report for 2014 in newly diagnosed gastrointestinal cancers and cancer deaths. The aim of the present study was to evaluate the association of Cd and Pb burden with the risk of gastrointestinal cancers in a hospital-based case-control study from southern regions of China, Chaoshan area. A total of 279 hospitalized patients were recruited in this study, of which 167 were gastrointestinal cancer cases (70 esophageal cancer, 51 gastric cancer, and 46 colorectal cancer), and 112 controls were recruited from two hospitals in the Chaoshan area of southeast China. Basic clinical data and information on gender, age, and other demographic characteristics were collected from medical records. Blood Cd and Pb levels were detected by graphite furnace atomizer absorption spectrophotometry (GFAAS). Blood Cd/Pb levels and over-limit ratios between cases and controls were compared by Mann-Whitney U and Kruskal-Wallis H tests. We used logistic regression to estimate odds ratios (ORs) as measures of relative risk and explored the relationships between blood Cd/Pb levels and gastrointestinal cancer risk and clinicopathological characteristics. Median levels of blood Cd and Pb in cases (2.12 and 60.03 μg/L, respectively) were significantly higher than those of controls (1.47 and 53.84 μg/L, respectively). The over-limit ratios for Cd (≥ 5 μg/L) and Pb (≥ 100 μg/L) in the cases were both higher than that of controls. Blood Cd levels had a tendency to accumulate in the human body with gender, age, and tobacco smoking, while blood Pb levels only were associated with tobacco smoking. The logistic regression model illustrated that gastrointestinal cancers were significantly associated with blood Cd levels and blood Pb levels. The concentrations of Cd and Pb in patients with T3 + T4 stage were markedly higher than in patients with T1 + T2. On the other hand, blood Cd levels were dramatically increased in the distant -metastasis (M1). Blood Cd and Pb levels are significantly higher in gastrointestinal cancers compared to controls. Cd and Pb appear to be risk factors for gastrointestinal cancers in Chaoshan region, and higher levels of Cd and Pb may promote the occurrence and progression of gastrointestinal cancers.