Biomonitoring of Trace Elements in Hair of Schoolchildren Living Near a Hazardous Waste Incinerator-A 20 Years Follow-Up

Evaluate the Work-Related Exposure of Vanadium on Scalp Hair Samples of Outdoor and Administrative Workers of Oil Drilling Field: Related Health Risks

Petrochemical facilities, including oil well drilling, are discharging resources of extensive noxious waste into the environment. The workers in different sections might be exposed to vanadium (V) through different routes (groundwater and soil), which is linked with extensive physiological disorders, hypertension, respiratory disorders, anemia, skin, and gastrointestinal disorders. This study determined the contents of V in a biological sample (scalp hair) of workers of different categories (outdoor and office workers) in an oil drilling field in Sindh, Pakistan. The environmental samples, groundwater, bottled mineral water, and soil samples were also analyzed for V. For comparative purposes, the scalp hair of age-matched male subjects residing in domestic areas of Hyderabad city, Pakistan, was also analyzed. Generally, the concentrations of V in groundwater near the oil drilling field and drilled soil illustrated significant variations. The results show that the vanadium concentration in the scalp hair of non-exposed referents (controls) and office workers (exposed referents) was 62% and 45% lower than those observed for outdoor drilling and cleaning mud workers. It was observed that high exposure to V in outdoor workers might be linked with different physiological disorders such as anemia, eye problems, and bronchial disorders.

Heavy Metal(oid)s Contamination and Potential Ecological Risk Assessment in Agricultural Soils

Soil pollution caused by heavy metal(oid)s has generated great concern worldwide due to their toxicity, persistence, and bio-accumulation properties. To assess the baseline data, the heavy metal(oid)s, including manganese (Mn), iron (Fe), Cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), lead (Pb), mercury (Hg), chromium (Cr), and cadmium (Cd), were evaluated in surface soil samples collected from the farmlands of Grand Forks County, North Dakota. Samples were digested via acid mixture and analyzed via inductively coupled plasma mass spectrometry (ICP MS) analysis to assess the levels, ecological risks, and possible sources. The heavy metal(oid) median levels exhibited the following decreasing trend: Fe > Mn > Zn > Ni > Cr > Cu > Pb > Co > As > Cd > Hg. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) suggested the main lithogenic source for the studied metal(oid)s. Metal(oid) levels in the current investigation, except Mn, are lower than most of the guideline values set by international agencies. The contamination factor (Cf), geo accumulation index (Igeo) and enrichment factor (EF) showed considerable contamination, moderate contamination, and significant enrichment, respectively, for As and Cd on median value basis. Ecological risk factor (Er) results exhibited low ecological risk for all studied metal(oid)s except Cd, which showed considerable ecological risk. The potential ecological risk index (PERI) levels indicated low ecological risk to considerable risk. Overall, the results indicate the accumulation of As and Cd in the study area. The high nutrients of the soils potentially affect their accumulation in crops and impact on consumers' health. This drives the impetus for continued environmental monitoring programs.

Effects of preterm birth and postnatal exposure to metal mixtures on neurodevelopment in children at 24 months of age

The effects of early-life metal exposure on neurodevelopment in very low birth weight preterm (VLBMP) children (with a birth weight of <1500 g and a gestational age of <37 weeks) have not been clearly established. We aimed to investigate associations of childhood exposure to multiple metals and preterm low birth weight with neurodevelopment among children at 24 months of corrected age. VLBWP children (n = 65) and normal birth weight term (NBWT) children (n = 87) were enrolled from Mackay Memorial Hospital in Taiwan between December 2011 and April 2015. Lead (Pb), cadmium (Cd), arsenic (As), methylmercury (MeHg), and selenium (Se) concentrations in the hair and fingernails were analyzed as biomarkers for metal exposure. The Bayley Scale of Infant and Toddler Development, Third Edition, was used to determine neurodevelopment levels. VLBWP children had significantly lower scores in all development domains compared to NBWT children. We also investigated preliminary exposure levels of VLBWP children to metals as reference values for future epidemiological and clinical survey. Fingernails are a useful biomarker for metal exposure to evaluate the effects on neurological development. A multivariable regression analysis revealed that fingernail Cd concentrations were significantly negatively associated with cognition (β = -0.63, 95% confidence interval (CI): -1.17 to -0.08) and receptive language function (β = -0.43, 95% CI: -0.82 to -0.04) among VLBWP children. VLBWP children with a 10-μg/g increase in the As concentration in their nails had a 8.67-point lower composite score in cognitive ability and a 1.82-point lower score in gross-motor functions. Effects of preterm birth and postnatal exposure to Cd and As were associated with poorer cognitive, receptive language, and gross-motor abilities. VLBWP children are at risk for neurodevelopmental impairments when exposed to metals. Further large-scale studies are needed assess to the risk of neurodevelopmental impairments when vulnerable children are exposed to metal mixtures.

Levels of Toxic and Essential Elements and Associated Factors in the Hair of Japanese Young Children

There is growing concern regarding the effects of toxic element exposure on the development of children. However, little is known about the level of toxic elements exposure in Japanese children. The purpose of this study was to assess the concentrations of multiple elements (aluminum, cadmium, lead, calcium, copper, iron, magnesium, sodium, zinc) in the hair of 118 Japanese young children and to explore the factors associated with their element levels. The element concentration was analyzed by ICP-MS, and children's food and water intake were assessed by the questionnaire. Results showed that there were no large differences between the level of elements in the hair of Japanese children and those of children in other developed countries. Girls had significantly higher levels of aluminum, copper, and iron (p = 0.000, 0.014, and 0.013, respectively), and boys had a higher level of sodium (p = 0.006). The levels of calcium, iron, magnesium, and sodium in nursery school children were significantly higher than those in kindergarten children (p = 0.024, 0.001, 0.046, and 0.029, respectively). Multiple regression analyses with controlling the confounding variables showed significant negative associations of frequency of yogurt intake with aluminum and lead levels (p = 0.015 and 0.037, respectively). When the children were divided into three groups based on the frequency of yoghurt consumption, viz. L (≤once a week), M (2 or 3 times a week), and H (≥4 to 6 times a week) group, the mean aluminum concentration (µg/g) in the L, M, and H groups was 11.06, 10.13, and 6.85, while the mean lead concentration (µg/g) was 1.76, 1.70, and 0.87, respectively. Our results suggested the validity of hair element concentrations as an exposure measure of essential elements and frequent yogurt intake as a viable measure for protecting children from toxic elements. However, these findings will need to be confirmed in more detailed studies with larger sample sizes in the future.

Levels of trace elements in human hair samples of adolescents living near petrochemical plants

The aim of the study is a comparative analysis to investigate human hair metal profiles of adolescents residing near petrochemical plants (Sicily, Italy). We selected the small town of Augusta, Gela, and Pace del Mela, and a control area made up of the towns characterized by low anthropogenic activity. Twenty trace elements were measured in samples of scalp hair from adolescents (11-14 years old) of both genders. Hair samples were cleaned using a rigorous cleaning method, mineralized, and processed for analyses by inductively coupled plasma-mass spectrometry (ICP-MS). In industrial sites, zinc was always the most abundant element, ranging from186 to 217 μg g^-1. Following zinc, the elements Al, Ba, Cu, Fe, and Sr were in the range 1-20 μg g^-1. The remaining elements had concentrations < 1 μg g^-1. The comparison with adolescents living in suburban area highlighted that As, Ba, Mn, Sr, U, and V have the highest median concentrations in an industrial location. An industrial factor (As, Mn, Sr, U, and V) and an urban factor (Cd, Cr, Cu, Mo, Ni, and Sb) were distinguished by the multivariate statistical analysis between a cohort residing in urban and industrial areas. Statistically significant differences (Kruskal-Wallis test, p < 0.05) between the genders were found for Ba, Mn, Ni, Sr, and V in all industrial sites with median concentrations higher in females' hair than males'. The data confirm that the study areas are heavily affected by industrial and urban emissions of metals and metalloids, representing a potential hazard to the local population.

Ribosomal DNA copy number associated with blood metal levels in school-age children: A follow-up study on a municipal waste incinerator in Zhejiang, China

To evaluate the body burdens of heavy metals and explore the impact of environmental metal exposure on ribosomal DNA (rDNA) or mitochondrial DNA (mtDNA) copy number (CN) variation in school-age children living near a municipal waste incinerator (MWI), we conducted a follow-up study in 2019. A total of 146 sixth-grade children from a primary school located 1.2 km away from the MWI were recruited for our study. Metals, including vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), stannum (Sn), stibium (Sb), thallium (Tl), and lead (Pb), were determined by an inductively coupled plasma mass spectrometer method. Real-time qPCR was used to measure the rDNA and mtDNA CN. The blood metal levels followed this order: Zn > Cu > Se > Pb > Mn > Sb > As > Ni > Cd > Co > Cr > Sn > V > Tl. Blood Cr level was significantly correlated with 18 S, 2.5 S, and 45 S CN (β = -0.25, -0.22, -0.26, p < 0.05); Ni was correlated with 5 S (β = -0.36, p < 0.01); Cu was correlated with 28 S, 18 S, and 5.8 S (β = -0.24, -0.24, -0.23, p < 0.05); while Zn was correlated with 18 S, 5.8 S, and 45 S (β = -0.28, -0.32, -0.26, p < 0.05). In conclusion, school-age children living near the MWI had lower blood metal levels compared to children recruited in 2013, while rDNA CN loss was found to be correlated to several heavy metals in these children.

Association between trace metals exposure and hearing loss

Background

Trace metals have side-effect on human health. The association between trace metals exposure and hearing loss remains unclear.

Methods

A total of 8,128 participants were exacted for analysis of association between trace metals and hearing loss from the database of the National Health and Nutrition Examination Survey (NHANES) (2013-2018). Multivariable logistic regression and restricted cubic spline models were used to examine the association between trace metals and hearing loss.

Results

Participants with hearing loss had a higher level of lead, cadmium, molybdenum, tin, thallium, and tungsten (all p < 0.05). After adjusting for confounders, compared with the reference of the lowest quartile, the ORs with 95%CIs for hearing loss across quartiles were 1.14 (0.86, 1.51), 1.49 (1.12, 1.98), 1.32 (0.97, 1.80) for cobalt, and 1.35 (0.98, 1.87), 1.58 (1.15, 2.16), 1.75 (1.28, 2.40) for tin. Individuals with the level of cobalt at third quartile had 49% higher risks of hearing loss than those at lowest quartile. And participants with highest quartile of tin had 1.75-folds risks of hearing loss than those with lowest quartile of tin. There were increasing trends in risks of hearing loss with a raised level of thallium (p for trend <0.05). Restricted cubic spline regression analysis indicated that there was a nonlinear association between hearing loss and the levels of tin (p for nonlinearity = 0.021). Subgroup analysis showed that individuals of female, without hypertension and diabetes, and with a higher level of low-density lipoprotein cholesterol had modified effects on the associations between hearing loss and exposure to tin.

Conclusions

Our study indicated that exposure to cobalt and tin were significantly associated with hearing loss.

Causal relationships between blood calcium, iron, magnesium, zinc, selenium, phosphorus, copper, and lead levels and multisystem disease outcomes in over 400,000 Caucasian participants

BACKGROUND & AIMS

Metal elements have been associated with a wide range of clinical outcomes. The available epidemiological evidence for these associations is often inconsistent and suffers from confounding and reverse causation. We aimed to explore the broad clinical effects of varying blood metal element levels and possible underlying mechanisms.

METHODS

We performed a two-sample Mendelian randomization (MR) analysis by using metal element-associated genetic loci as instrumental variable to evaluate the causal associations between blood metal element levels and 1050 disease outcomes in a UK Biobank cohort. A total of 408,910 White British participants were enrolled in the analysis. We further used the metal element-related genes and disease-related genes to construct a protein-protein interaction (PPI) network.

RESULTS

Eight metal elements were associated with 63 diseases in total. Notably, we found nine pairs of suggestive evidence between two different metal elements for the same disease. Selenium and lead share some of the associated clinical outcomes, including diabetes mellitus, type 2 diabetes, lymphoid leukemia, and acute pharyngitis. Lead and zinc share the associated disease of acquired hypothyroidism. Iron and copper share the associated disease of arthropathies. Copper and zinc share the associated disease of occlusion of cerebral arteries. Calcium and zinc share the associated disease of arthropathies. In addition, the PPI network provided potential links between metal elements and disease outcomes at the genetic level.

CONCLUSIONS

Our MR study of eight metal elements comprehensively characterized their shared and unique clinical effects, highlighting their potential causal roles in multiple diseases. Given the modifiable nature of blood metal elements and the potential for clinical interventions, these findings warrant further investigation.

Exposure to metal mixture and growth indicators at 4-5 years. A study in the INMA-Asturias cohort

BACKGROUND

Exposure to toxic and non-toxic metals impacts childhood growth and development, but limited data exists on exposure to metal mixtures. Here, we investigated the effects of exposure to individual metals and a mixture of barium, cadmium, cobalt, lead, molybdenum, zinc, and arsenic on growth indicators in children 4-5 years of age.

METHODS

We used urine metal concentrations as biomarkers of exposure in 328 children enrolled in the Spanish INMA-Asturias cohort. Anthropometric measurements (arm, head, and waist circumferences, standing height, and body mass index) and parental sociodemographic variables were collected through face-to-face interviews by trained study staff. Linear regressions were used to estimate the independent effects and were adjusted for each metal in the mixture. We applied Bayesian kernel machine regression to examine non-linear associations and potential interactions.

RESULTS

In linear regression, urinary levels of cadmium were associated with reduced arm circumference (β_adjusted = -0.44, 95% confidence interval [CI]: -0.73, -0.15), waist circumference (β_adjusted = -1.29, 95% CI: -2.10, -0.48), and standing height (β_adjusted = -1.09, 95% CI: -1.82, -0.35). Lead and cobalt concentrations were associated with reduced standing height (β_adjusted = -0.64, 95% CI: -1.20, -0.07) and smaller head circumference (β_adjusted = -0.29, 95% CI: -0.49, -0.09), respectively. However, molybdenum was positively associated with head circumference (β_adjusted = 0.22, 95% CI: 0.01, 0.43). BKMR analyses showed strong linear negative associations of cadmium with arm and head circumference and standing height. BKMR analyses also found lead and cobalt in the metal mixture were related to reduce standing height and head circumference, and consistently found molybdenum was related to increased head circumference.

CONCLUSION

Our findings suggest that exposure to metal mixtures impacts growth indicators in children.

Assessment of the Ecotoxicity of Pollution by Potentially Toxic Elements by Biological Indicators of Haplic Chernozem of Southern Russia (Rostov region)

The content of various chemical elements such as metals, metalloids, and nonmetals in the environment is associated with natural and anthropogenic sources. It is necessary to normalize the content of metals, metalloids, and nonmetals as potentially toxic elements (PTE) in the Haplic Chernozem. The soils of the Southern Russia are of high quality and fertility. However, this type of soil, like Haplic Chernozem, is subject to contamination with a wide range of PTE. The aim of the work was to rank metals, metalloids, and nonmetals by ecotoxicity in Haplic Chernozem. To assess the ecotoxicity of chernozem, data for 15 years (2005-2020) were used. Biological indicators used to assess the ecotoxicity of Haplic Chernozem: catalase activity, cellulolytic activity, number of bacteria, Azotobacter spp. abundance, to change of length of radish's roots. Based on these biological indicators, an integral indicator of the state of Haplic Chernozem was calculated. The ecotoxicity of 23 metals (Cd, Hg, Pb, Cr, Cu, Zn, Ni, Co, Mo, Mn, Ba, Sr, Sn, V, W, Ag, Bi, Ga, Nb, Sc, Tl, Y, Yb), 5 metalloids (B, As, Ge, Sb, Te) and 2 nonmetals (F, Se) as priority pollutants. It is proposed to distinguish three hazard classes of metals, metalloids, and nonmetals to Haplic Chernozem: I class - Te, Ag, Se, Cr, Bi, Ge, Sn, Tl, Hg, Yb, W, Cd; II class - As, Co, Sc, Sb, Cu, Ni, B, Nb, Pb, Ga; III class - Sr, Y, Mo, Zn, V, Ba, Mn, F. It is advisable to use the results of the study for predictive assessment of the impact of metals, metalloids, and nonmetals on the ecological state of the soil during pollution.

Heavy metal pollution in the soil around municipal solid waste incinerators and its health risks in China

OBJECTIVE

In China, municipal solid waste (MSW) incineration (MSWI) has been increasing in recent years. However, little is known about how the operation of incinerators can affect levels of heavy metals (HMs) in nearby soils or about the possible associated health risks. It is necessary to understand the degree of enrichment of HMs and health risks to people living nearby.

METHODS

Previous studies (2002-2021) regarding soil HMs near MSW incinerators were collected, and a cluster and factor analysis was used to evaluate the accumulation trends and distribution characteritics of HMs. The soil contamination degrees and the consequent health risks were then assessed.

RESULTS

Cd (0.24 ± 0.16 mg kg-1) is typically accumulated in the topsoil near incinerators, and this is followed by Hg (0.13 ± 0.09 mg kg-1). Most of the health risk due to the total HMs is derived from dermal contact. Dermal contact with Cd and As contributes to more than 67% of the non-carcinogenic risk, while dermal contact with As contributes to more than 99% of the carcinogenic risk (CR). Furthermore, 81.43% of adult males and 76.85% of adult females suffer from CR levels greater than 10-4 due to dermal exposure to As.

CONCLUSIONS

Soils near incinerators indicated light pollution and moderate potential ecological risk, especially with regard to Cd and Hg contamination. Undeniably, there was no significant difference between the health risks from soil HMs near incinerators and from arable land at the national level. It is suggested to reduce the input quantity of HMs by taking advantage of the nationwide implementation of MSW classification and upgrading air pollution control devices for further HM emission reductions.

Effects of soil lead exposure and land use characteristics on neurodevelopment among children under 3 years of age in northern Taiwan

Lead (Pb) exposure increases the risks of neurodevelopmental disorders in children. Child-specific activities and land use scenarios may lead to elevated opportunities for Pb exposure through the soil. Therefore, we investigated hair and fingernail Pb concentrations among young children in northern Taiwan, in relation to soil Pb pollution and land use characteristics. We also explored the effect of the Pb exposure burden and land use scenarios on neurobehavioral development. In total, 139 healthy children under 3 years of age were recruited in October 2011 to April 2014. Pb levels in hair and fingernail samples were determined using an inductively coupled plasma/mass spectrometer. Pb concentrations in soils and land use types surrounding the children's homes were accessed by a geographic information system to identify any associations with hair Pb levels. The Bayley Scales of Infant and Toddler Development (Bayley-III) were used to evaluate the cognitive, language, and motor development of the children. A multivariable regression model was performed to assess the effects of soil Pb levels and land-use status on Pb exposure in children, as well as associations of Pb exposure and land-use scenarios with neurodevelopmental abilities. Geometric mean Pb concentrations in hair, fingernails, and soil were 2.9 ± 4.8 μg/g, 0.8 ± 5.1 μg/g, and 20.8 ± 4.3 mg/kg, respectively. The multivariable analysis indicated that soil Pb concentrations and green areas around residences had potential links with Pb exposure among children in northern Taiwan. Hair Pb concentrations were negatively associated with expressive language scores. Soil Pb exposure was positively associated with hair Pb concentrations. Land use types around the children's homes in northern Taiwan were associated with their neurodevelopment. Increased green areas were negatively associated with hair Pb concentrations. Living near a highway may have had negative impacts on gross motor scores. A healthy residence can avoid potential health risks for children during their early life.

Environmental impact and human health risks of air pollutants near a large chemical/petrochemical complex: Case study in Tarragona, Spain

Chemical industries and oil refineries are known emission sources of environmental contaminants, such as metals/metalloids, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), among others. Based on the toxicological potential of these pollutants, harmful health effects can be expected for the population living near these facilities. One of the largest chemical/petrochemical complexes in Europe is located in Tarragona County (Catalonia, Spain). In the last two decades, a number of investigations aimed at assessing the environmental impact of air pollutants potentially emitted by this industrial complex have been carried out. The present paper is a review of the available scientific information on the levels of air pollutants related with the activities of this chemical/petrochemical complex. Although there are currently some data on the environmental burdens of metals/metalloids, PAHs, VOCs and PCDD/Fs, there is an evident lack of specific biological monitoring studies on human health. Taking into account the amount of chemicals released to air and their toxicity, it is essential to perform an in-depth analysis of the current health status of the population living in Tarragona County.

Concentrations of arsenic and vanadium in environmental and biological samples collected in the neighborhood of petrochemical industries: A review of the scientific literature

Petrochemical facilities, including oil refineries, are emission sources of a wide range of environmental pollutants such as trace elements, volatile organic compounds, and polycyclic aromatic hydrocarbons, among others. Populations living near this kind of facilities may be potentially exposed to contaminants, which are, in turn, associated with a wide range of adverse effects. In our laboratory, we have shown that the environmental concentrations of trace elements near the petrochemical complex of Tarragona County (Spain), which is among the largest complexes in the European Union, should not be a relevant pollution source for these elements, with the exception of arsenic (As) and vanadium (V). Moreover, the International Agency for Research on Cancer (IARC) classified As and V as Group 1 and Group 2B, respectively. Based on it, the present paper was aimed at reviewing the available scientific information on the occurrence of As and V in the vicinity of petrochemical complexes worldwide, considering environmental matrices (air, dust, sediments, soil, and water), as well as biological samples (blood, hair, and urine). In general, levels of As and V in environmental matrices showed higher fluctuation throughout the world and was highly dependent on the samples zone while levels of both elements in urinary samples from subjects living near a petrochemical area were higher than those of population living further.

Temporal trend of the dietary exposure to metals/metalloids: A case study in Tarragona County, Spain

In 2018, samples of various food groups were randomly purchased in different establishments of Tarragona County (Catalonia, Spain). The levels of As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl and V were determined in the analyzed foodstuffs and their dietary intakes were estimated. Manganese was the element showing the highest concentration, while Be, Cr and Tl were not detected in any of the samples. Fish and shellfish was the only food group with detectable traces of all the remaining elements. The current levels were compared with the results of two previous surveys conducted in 1998 and 2013 in the same area. Although the levels of the analyzed elements in foodstuffs increased during the period 2013-2018, their intakes decreased by an average of 60%, due to consumption patterns changes by the population. Children and adolescents exceeded the maximum recommended intake of Ni set by the EFSA, while the dietary exposure to Pb for children was also above safety values. Compared with the concentrations found in 2013, Ni was the only element showing an increase, as well as an increase of human dietary intake. Meat, vegetables and milk were identified as the main contributors to Ni exposure. This trend was also correlated with changes in the biological burden of the same elements previously reported for the population of the area, for whom an increase of Ni in lungs was reported. Based on these results, Ni should be included as a target metal by food safety authorities, being suggested its inclusion in future Total Diet Studies.

Hair mineral analysis in the population of students living in the Lower Silesia region (Poland) in 2019: Comparison with biomonitoring study in 2009 and literature data

The paper presents a comparative analysis of biomonitoring research results using hair mineral analysis today and 10 years ago. The aim of the present work was to examine the impact of individual factors, on the content of elements in human hair. The mineral analysis of 115 hair samples was carried out using ICP-OES and AAS technique. It was shown that calcium, barium, copper, mercury, magnesium, manganese and selenium content depend on gender and is higher for women. Statistically significant synergistic correlations were identified between the following pairs of elements: (Ca-Mg), (P-S), (Mo-Sb) and (Ba-Pb). The results of the present work were compared with the previous assessment in 2009 on students of the same age. The content of most of the heavy metals in hair was reduced significantly, which is a sign of the improving state of the local environment. The greatest decrease was recorded for silver (96.6%), arsenic (93.4%), mercury (45.1%), lead (67.7%), antimony (55.2%), thallium (10 times) and cobalt (93.7%). The level of the following elements increased: Ba: 27.3%, Cu: 28.5%, Ni: 22.4%, Ti: 191%, Zn: 11.0%. Changes in the content of most heavy metals in hair have been noted, as well as changes of reference ranges, which may indicate an improvement in the state of the environment in Wrocław, Lower Silesia (Poland) over the last 10 years. These results were confirmed by biomonitoring studies carried out with human hair, which was shown to be a reliable biomarker of human exposure to toxic elements.

The effects of some essential and toxic metals/metalloids in COVID-19: A review

Thousands of studies have been conducted in order to understand in depth the characteristics of the novel coronavirus SARS-CoV-2, its infectivity and ways of transmission, and very especially everything related to the clinical and severity of the COVID-19, as well as the potential treatments. In this sense, the role that essential and toxic metals/metalloids have in the development and course of this disease is being studied. Metals/metalloids such as arsenic, cadmium, lead, mercury or vanadium, are elements with known toxic effects in mammals, while trace elements such as cobalt, copper, iron, manganese, selenium and zinc are considered essential. Given the importance of metals/metalloids in nutrition and human health, the present review was aimed at assessing the relationship between various essential and toxic metals/metalloids and the health outcomes related with the COVID-19. We are in the position to conclude that particular attention must be paid to the load/levels of essential trace elements in COVID-19 patients, mainly zinc and selenium. On the other hand, the exposure to air pollutants in general, and toxic metal/metalloids in particular, should be avoided as much as possible to reduce the possibilities of viral infections, including SARS-CoV-2.

Decreasing temporal trends of polychlorinated dibenzo-p-dioxins and dibenzofurans in adipose tissue from residents near a hazardous waste incinerator

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are very toxic chemicals which are emitted in waste incineration and whose exposure has important adverse effects for the human health. In 2019, adipose tissue samples were collected from 15 individuals with a median age of 61 years, who had been living near a hazardous waste incinerator in Constantí (Spain). The content of PCDD/Fs in each sample was analyzed. The results were compared with data from previous studies, conducted before (1998) and after (2002, 2007 and 2013) the facility started to operate, and based on populations of similar age. In 2019, the mean concentration of PCDD/Fs in adipose tissue was 6.63 pg WHO-TEQ/g fat, ranging from 0.95 to 12.95 pg WHO-TEQ/g fat. A significant reduction was observed with respect to the baseline study (1998), when a mean PCDD/Fs concentration of 40.1 pg WHO-TEQ/g fat was found. Moreover, the current level was much lower than those observed in the 3 previous studies (9.89, 14.6 and 11.5 pg WHO-TEQ/g fat in 2002, 2007 and 2013, respectively). The body burdens of PCDD/Fs were strongly correlated with age. The significant reduction of PCDD/Fs levels in adipose tissue fully agreed with the decreasing trend of the dietary intake of PCDD/Fs by the population of the zone (from 210.1 pg I-TEQ/day in 2018 to 8.54 pg WHO-TEQ/day in 2018). Furthermore, a similar decrease has been also observed in other biological, such as breast milk and plasma. The current data in adipose tissue, as well as those in other biological monitors, indicate that the population living near the HWI is not particularly exposed to high levels of PCDD/Fs. However, biomonitoring studies cannot differentiate the impact of the HWI emissions from food consumption patterns. This question can be only solved by conducting complementary investigations and contrasting the results of monitoring and epidemiological studies.

Trends of Polychlorinated Compounds in the Surroundings of a Municipal Solid Waste Incinerator in Mataró (Catalonia, Spain): Assessing Health Risks

Since 2008, the environmental levels of polychlorinated compounds near a municipal solid waste incinerator in Mataró (Catalonia, Spain) have been periodically monitored. The present study aimed at updating the data regarding the temporal changes occurred between 2015 and 2017, when air and soil samples were collected again, and the concentrations of the same chemical pollutants (i.e., polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs)) were analysed. Furthermore, the health risks associated with their human exposure were also evaluated. The levels of all the contaminants in soil were far below the threshold established by regional and national legislations, also being lower than those observed in previous surveys. A similar trend was also noted for PCDD/Fs in air samples, while airborne PCBs were the only group of chemicals whose levels significantly increased. In any case, the global assessment of the data regarding the different pollutants and matrices indicates that there has not been a general increase in the environmental pollution around the facility. In addition, the environmental exposure to PCDD/Fs and PCBs by the population living nearby is still clearly lower than the dietary intake of these same chemical pollutants.

Trace Elements in Blood of the Population Living near a Hazardous Waste Incinerator in Catalonia, Spain

In 2012, the concentrations of trace elements (As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl, and V) were measured in blood samples of the population living in the vicinity of a hazardous waste incinerator (HWI) located in Tarragona County (Catalonia, Spain). This study is part of a wide surveillance program aimed at assessing the impact of the facility on the public health conducted since 1998, before the HWI started operating. Lead was the metal occurring with the highest concentration (21.7 μg kg^-1), followed by Mn (19.7 μg kg^-1) and Hg (4.62 μg kg^-1). Arsenic (6.99 μg kg^-1) showed a low detection rate (49%), while the rest of the analyzed trace elements were not detected. In 2017, a new sampling campaign was conducted, and three new trace elements (Co, Cu, and Sb) were added. In the most recent survey, Cu reached a mean concentration of 931 μg kg^-1, up to 60-fold higher than that corresponding to the remaining trace elements. Relatively high levels were also found for Sb (16.0 μg kg^-1), Mn (13.9 μg kg^-1), and Pb (13.0 μg kg^-1). In comparison with the baseline study (1998), Hg, Mn, and Pb significantly decreased over time. Some trace elements showed significant differences according to sex, age, and area of residence. In general, the concentrations of trace elements in blood were similar to, or even lower than, those reported in the scientific literature. Hence, the exposure to trace elements does not mean any additional health risk for the population living near the HWI. This conclusion is in agreement with other studies carried out in the framework of this surveillance program, in which trace elements have been measured in different biological matrices, such as hair and autopsy tissues (brain, bone, kidney, liver, and lungs).

Adverse health effects for populations living near waste incinerators with special attention to hazardous waste incinerators. A review of the scientific literature

Incinerators of municipal, hazardous and medical wastes are sources of emissions of toxic pollutants, being polychlorinated dibenzo-p-dioxins and dibenzofurans, as well as a number of heavy metals of special concern. Moreover, waste incineration also generates ashes that must be properly disposed. In all countries, waste management is currently being an issue of tremendous importance. While the treatment and disposal of municipal solid waste (MSW) is a problem in the entire world, in industrialized countries, the management of hazardous waste (HW) is an additional issue of important concern. While the available scientific information on the environmental impact and the health risks of MSWIs is quite considerable, that related with the potential adverse health effects for the populations living near HWIs is much more reduced. In this paper, we have reviewed the information on health effects-including the incidence of cancer and cancer mortality-for the people residing in the vicinity of HWIs. For a better understanding of the problem, some studies on cancer and other adverse health effects near MSWIs have been also reviewed. Special attention has been paid to the HWI of Constantí (Catalonia, Spain) on which the most complete information among all HWIs in the entire world is available. In our conclusions, a series of important issues/questions are raised: is really safe the limit value of 0.1 ng TEQ/Nm³ for PCDD/Fs to protect human health? Where are the evidences on this? On the other hand, to date, risk assessment studies have been only focused on certain substances; heavy metals and PCDD/Fs. Studies have not included those chemicals that are not routinely analyzed, being even some of them probably unknown right now. Moreover, what about potential interactions among chemicals in order to estimate the carcinogenic and non-carcinogenic risks for the population living near incinerators? Complete epidemiological studies are clearly necessary.

Biomonitoring of co-exposure to bisphenols by consumers of canned foodstuffs

For non-occupationally exposed adults, dietary intake is the main route of exposure to bisphenols (BPs), with canned foodstuffs playing a key role. This study was aimed at biomonitoring bisphenol A (BPA) and 5 more BP analogues (BPB, BPE, BPF, BPAF and BPZ) in spot urine and blood samples of a cohort of adults, who followed a diet based on a high consumption of canned food. To the best of our knowledge, this is the first study aimed at assessing the co-exposure of BP analogues in food and biological samples after a two-day duplicate diet study. The estimated total dietary exposure was 0.37 and 0.045 µg/kg body weight/day, for the canned-diet and control groups, respectively. BPA was the compound with the highest concentration in urine in comparison with the values of the remaining BP analogues. A high detection rate of BPA was noted in urine for both groups, 96% for the canned-diet group and 90% for the control group, while in blood it could be only quantified in 6% of the samples. The identification of other analogues was hardly related to diet, so it could be the result of other potential exposure sources, such as personal care products (PCPs) or air inhalation. After 2 days, the excretion of BPA was considerably higher in the canned-diet group subjects than those in the control group (7.02 vs. 1.89 µg/day), confirming that diet and canned foodstuffs are the main route of exposure to BPA. Anyhow, the temporary tolerable daily intake (t-TDI) established by the EFSA was not exceeded, even by those consumers with a diet rich in canned food. Moreover, spot urine samples provided accurate information about exposure and excretion of BPA, being the 4 h, instead of 24 h, the optimal sampling interval, when the collection of spot urine samples is not possible.

Biomonitoring of Trace Elements in Subjects Living Near a Hazardous Waste Incinerator: Concentrations in Autopsy Tissues

The only hazardous waste incinerator (HWI) in Spain started to operate in 1999. Twenty years later, the levels of 11 trace elements (As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl and V) were analyzed in five different autopsy tissues (kidney, liver, brain, bone and lung) from 20 individuals who had been living near the facility. In 2019, As, Be, Tl and V were not detected in any of the analyzed tissues, while Hg could be only quantified in very few samples. The highest levels of Cd and Pb were found in kidney and bone, respectively, while those of Mn were observed in liver and kidney. In turn, the mean concentrations of Cr and Sn were very similar in all tissues. A consistent temporal trend (1998-2019) was only found for Cr and Pb. On the one hand, the mean Cr concentrations in kidney and bone have increased progressively since 1998. In contrast, the mean levels of Pb decreased significantly over time, probably due to ban of Pb as gasoline additive. The data global analysis indicates that the emissions of trace elements by the HWI have not increased the exposure and/or accumulation of these elements in individuals living near the facility.