Correlation between the arsenic concentrations in the air and the SMR of lung cancer

Carcinogenic effect of arsenic in digestive cancers: a systematic review

BACKGROUND

The carcinogenic effect of arsenic (As) has been documented in lung, bladder and skin cancers but remains unclear for digestive cancers, although metabolic pathways of As and recent data suggest that it may be an important determinant in these malignancies as well.

OBJECTIVE

This study aimed to systematically review the available literature investigating the potential association between As and digestive cancers.

METHODS

An extensive search was conducted in Medline Ovid SP, Cochrane, PubMed, Embase.com, Cochrane Library Wiley, Web of Science and Google Scholar. Studies providing original data in humans, with As measurement and analysis of association with digestive cancers including esogastric cancers (esophagus and stomach), hepato-pancreatico-biliary (HPB) cancers (including biliary tract, liver and pancreas) and colorectal cancers were eligible.

RESULTS

A total of 35 studies were identified, 17 ecological, 13 case-control and 5 cohort studies. Associations between As and digestive cancers were reported for both risks of incidence and cancer-related mortality. Overall, 43% (3/7) and 48% (10/21) studies highlighted an association between As and the incidence or the mortality of digestive cancers, respectively.

CONCLUSIONS

A substantial proportion of studies exploring the potential link between As and digestive cancers suggested an association, particularly in HPB malignancies. These findings emphasize the need to further investigate this topic with dedicated and high-quality studies, as it may have an important impact, including for prevention strategies.

Arsenic in Mining Areas: Environmental Contamination Routes

The emission and accumulation of toxic elements such as arsenic in various environmental compartments have become increasingly frequent primarily due to anthropogenic actions such as those observed in agricultural, industrial, and mining activities. An example of environmental arsenic contamination in Brazil exists in the city of Paracatu, MG, due to the operation of a gold mine. The aim of this work is to evaluate the routes and effects of arsenic contamination in environmental compartments (air, water, and soil) and environmental organisms (fish and vegetables) from mining regions as well as the trophic transfer of the element for a risk assessment of the population. In this study, high levels of arsenic were found in the waters of the Rico stream ranging from 4.05 µg/L during the summer season to 72.4 µg/L during the winter season. Moreover, the highest As concentration was 1.668 mg kg^-1 in soil samples, which are influenced by seasonal variation and by proximity to the gold mine. Inorganic and organic arsenic species were found above the allowed limit in biological samples, indicating the transfer of arsenic found in the environment and demonstrating a great risk to the population exposed to this area. This study demonstrates the importance of environmental monitoring to diagnose contamination and encourage the search for new interventions and risk assessments for the population.

Speciation and source changes of atmospheric arsenic in Qingdao from 2016 to 2020 - Response to control policies in China

Arsenic (As) is a toxic pollutant in the atmosphere. The atmospheric As concentration is high over the East Asian continent. At present, there is less research on the long-term trend of atmospheric arsenic pollution, which is not conducive to understanding its behavior. Total suspended particulate matter (TSP) samples were collected in Qingdao in autumn and winter from 2016 to 2020 to analyze total arsenic (TAs), As(V) and As(III). The interannual variation patterns, influencing factors and health risks of arsenic concentrations in aerosols were discussed. The results showed that As(V) is the dominant species of arsenic in aerosols. The average concentration of TAs gradually decreased and the proportion of As(III) increased during autumn and winter from 2016 to 2020. The levels of TAs, As(V) and As(III) in aerosols increased during the heating period and on polluted days. Negative correlation between TAs/TSP and TSP indicated that higher concentrations of TSP in the atmosphere would reduce the content of TAs in particulate matter. The increase of secondary aerosol particles played a dilution effect. Mobile source emissions, biomass and coal combustion were main sources of atmospheric arsenic. The distribution range of large potential sources of atmospheric arsenic decreased from 2016 to 2020, and concentrated, mainly in parts of Shandong province and its offshore areas. Local sources contributed the most to atmospheric arsenic pollution in Qingdao in autumn and winter. TAs, As(V) and As(III) posed a low non-carcinogenic risk and a negligible carcinogenic risk to adults and children. This study reveals the influence of strict air pollution control policies on the speciation and source of arsenic in aerosols.

Temporal trend of arsenic in outdoor air PM2.5 in Wuhan, China, in 2015-2017 and the personal inhalation of PM-bound arsenic: implications for human exposure

Arsenic in fine air particulate matter (PM_2.5) has been identified as an important factor responsible for the morbidity of lung cancer, which has increased sharply in many regions of China. Some reports in China have shown that arsenic in the air exceeds the ambient air quality standard value, while long-term airborne arsenic concentrations in central China and human exposure via inhalation of PM-bound arsenic (inhalable airborne PM) have not been well characterized. In this study, 579 outdoor air PM_2.5 samples from Wuhan, a typical city in central China, were collected from 2015 to 2017, and arsenic was measured by inductively coupled plasma-mass spectrometry. Personal exposure to PM-bound arsenic via inhalation and urinary arsenic concentration were also measured. The concentrations of arsenic in PM_2.5 were in the range of 0.42-61.6 ng/m³ (mean 8.48 ng/m³). The average concentration of arsenic in 2015 (10.7 ng/m³) was higher than that in 2016 (6.81 ng/m³) and 2017 (8.18 ng/m³), exceeded the standard value. The arsenic concentrations in spring and winter were higher than those in summer and autumn. No significant differences (p > 0.05) were found among different sites. The daily intake of arsenic inhalation based on PM₁₀ samples collected by personal samplers (median, 10.8 ng/m³) was estimated. Urban residents inhaled higher levels of PM-bound arsenic than rural residents. Daily intake of arsenic via inhalation accounted for a negligible part (< 1%) of the total daily intake of arsenic (calculated based on excreted urinary arsenic); however, potential associations between the adverse effects (e.g., lung adenocarcinoma) and inhaled PM-bound arsenic require more attention, particularly for those who experience in long-term exposure. This study is the first report of a 3-year temporal trend of airborne PM_2.5-bound arsenic in central China.

The distance-to-source trend in vanadium and arsenic exposures for residents living near a petrochemical complex

Biological monitoring of vanadium (V) and arsenic (As) for residents living near a big petrochemical complex has not been previously studied. This study aims to investigate distance-to-source trends in urinary levels and dispersion-estimated concentrations of V and As in areas surrounding a petrochemical complex in central Taiwan. Our study subjects were 1424 residents living in the townships up to ~40 km from the petrochemical complex, and categorized as near (Zone A), further (Zone B) and furthest (Zone C) from the complex. Urinary and ambient V and As levels were analyzed by inductively coupled plasma mass spectrometry. Two-stage dispersion model was used to estimate V and As concentrations at each study subject's address. Multiple linear regression models were used to study the effects of distance-to-source and estimated air concentrations of V and As on the urinary V and As levels of study subjects. Area-wide levels of both V and As showed a high-to-low trend in urinary levels (μg/g-creatinine) from Zone A (V with 2.86±2.30 and As with 104.6±147.9) to Zone C (V with 0.73±0.72 and As with 73.8±90.8). For study subjects, urinary V and As levels were decreased by 0.09 and 1.17 μg/g-creatinine, respectively, with 1 km away from the emission source of the petrochemical complex, and urinary V levels were significantly elevated by 0.38 μg/g-creatinine with a 1 ng/m(3) increase in estimated ambient V concentrations at their addresses. Our study concludes a distance-to-source gradient in V and As exposures exists for residents living near a petrochemical complex with oil refineries and coal-fired power plants and two-stage dispersion model can predict such a trend for V when inhalation is the major exposure route, but not for As that exposure may be from multiple sources and exposure routes.

Association between exposure to low to moderate arsenic levels and incident cardiovascular disease. A prospective cohort study

BACKGROUND

Long-term exposure to high levels of arsenic is associated with increased risk for cardiovascular disease, whereas risk from long-term exposure to low to moderate arsenic levels (< 100μg/L in drinking water) is unclear.

OBJECTIVE

To evaluate the association between long-term exposure to low to moderate arsenic levels and incident cardiovascular disease.

DESIGN

Prospective cohort study.

SETTING

The Strong Heart Study baseline visit between 1989 and 1991, with follow-up through 2008.

PATIENTS

3575 American Indian men and women aged 45 to 74 years living in Arizona, Oklahoma, and North and South Dakota.

MEASUREMENTS

The sum of inorganic and methylated arsenic species in urine at baseline was used as a biomarker of long-term arsenic exposure. Outcomes were incident fatal and nonfatal cardiovascular disease.

RESULTS

A total of 1184 participants developed fatal and nonfatal cardiovascular disease. When the highest and lowest quartiles of arsenic concentrations (> 15.7 vs. < 5.8 μg/g creatinine) were compared,the hazard ratios for cardiovascular disease, coronary heart disease, and stroke mortality after adjustment for sociodemographic factors, smoking, body mass index, and lipid levels were 1.65 (95%CI, 1.20 to 2.27; P for trend < 0.001), 1.71 (CI, 1.19 to 2.44; P for trend < 0.001), and 3.03 (CI, 1.08 to 8.50; P for trend = 0.061),respectively. The corresponding hazard ratios for incident cardiovascular disease, coronary heart disease, and stroke were 1.32 (CI,1.09 to 1.59; P for trend = 0.002), 1.30 (CI, 1.04 to 1.62; P for trend = 0.006), and 1.47 (CI, 0.97 to 2.21; P for trend = 0.032).These associations varied by study region and were attenuated after further adjustment for diabetes, hypertension, and kidney disease measures.

LIMITATION

Direct measurement of individual arsenic levels in drinking water was unavailable.

CONCLUSION

Long-term exposure to low to moderate arsenic levels was associated with cardiovascular disease incidence and mortality.

Exposure to arsenic in urban and rural areas and effects on thyroid hormones

CONTEXT

Arsenic is a ubiquitous element present in urban air as a pollutant, and it may interfere with thyroid hormones.

OBJECTIVE

To evaluate the association between the personal exposure to arsenic and levels of TSH, fT4, fT3, and Tg in urban and rural workers.

MATERIALS AND METHODS

Total urinary arsenic and thyroid markers were obtained from 108 non-smoking traffic policemen and 77 subjects working as roadmen in a rural area. Fifty subjects were monitored to evaluate airborne exposure to arsenic.

RESULTS

The mean value of exposure to arsenic was 2.9 µg/m(3) in traffic policemen, while the mean value was less than 0.1 µg/m(3) in roadmen. The mean values of urinary arsenic (10.4 μg/g creatinine vs. 5.2 μg/g creatinine; p = 0.000), TSH (1.6 µlU/ml vs. 1.3 µlU/ml; p = 0.006), fT3 (3.5 pg/ml vs. 3.7 pg/ml; p = 0.000), fT4 (1.2 ng/dl vs. 1.3 ng/dl; p = 0.000) and Tg (42.8 ng/ml vs. 36.1 ng/ml; p = 0.04) were significantly different between traffic policemen and roadmen. In traffic policemen, urinary arsenic and arsenic in the air were correlated to the airborne arsenic and TSH values, respectively. Urinary arsenic was correlated to TSH, Tg, fT3, and fT4 values. The multiple linear regression models showed the following associations: i) among urinary arsenic, arsenic in the air and job title; ii) among TSH, fT3, Tg and urinary arsenic; and iii) between fT4 and both urinary arsenic and alcohol intake.

CONCLUSION

These results provide information about the relationship between exposure to arsenic and thyroid markers and may be useful for other categories of outdoor workers who are similarly exposed.

Arsenic exposure and cardiovascular disease: an updated systematic review

In epidemiologic studies, high-chronic arsenic exposure has been associated with cardiovascular disease, despite methodological limitations. At low-moderate arsenic levels, the evidence was inconclusive. Here, we update a previous systematic review (Am J Epidemiol 2005;162:1037-49) examining the association between arsenic exposure and cardiovascular disease. Eighteen studies published since 2005 were combined with 13 studies from the previous review. We calculated pooled relative risks by comparing the highest versus the lowest exposure category across studies. For high exposure (arsenic in drinking water > 50 μg/L), the pooled relative risks (95 % confidence interval) for cardiovascular disease, coronary heart disease, stroke, and peripheral arterial disease were 1.32 (95 % CI:1.05-1.67), 1.89 (95 % CI:1.33-2.69), 1.08 (95 % CI:0.98-1.19), and 2.17 (95 % CI:1.47-3.20), respectively. At low-moderate arsenic levels, the evidence was inconclusive. Our review strengthens the evidence for a causal association between high-chronic arsenic exposure and clinical cardiovascular endpoints. Additional high quality studies are needed at low-moderate arsenic levels.

Quantifying uncertainty in the measurement of arsenic in suspended particulate matter by Atomic Absorption Spectrometry with hydride generator

Arsenic is the toxic element, which creates several problems in human being specially when inhaled through air. So the accurate and precise measurement of arsenic in suspended particulate matter (SPM) is of prime importance as it gives information about the level of toxicity in the environment, and preventive measures could be taken in the effective areas. Quality assurance is equally important in the measurement of arsenic in SPM samples before making any decision. The quality and reliability of the data of such volatile elements depends upon the measurement of uncertainty of each step involved from sampling to analysis. The analytical results quantifying uncertainty gives a measure of the confidence level of the concerned laboratory. So the main objective of this study was to determine arsenic content in SPM samples with uncertainty budget and to find out various potential sources of uncertainty, which affects the results. Keeping these facts, we have selected seven diverse sites of Delhi (National Capital of India) for quantification of arsenic content in SPM samples with uncertainty budget following sampling by HVS to analysis by Atomic Absorption Spectrometer-Hydride Generator (AAS-HG). In the measurement of arsenic in SPM samples so many steps are involved from sampling to final result and we have considered various potential sources of uncertainties. The calculation of uncertainty is based on ISO/IEC17025: 2005 document and EURACHEM guideline. It has been found that the final results mostly depend on the uncertainty in measurement mainly due to repeatability, final volume prepared for analysis, weighing balance and sampling by HVS. After the analysis of data of seven diverse sites of Delhi, it has been concluded that during the period from 31^st Jan. 2008 to 7^th Feb. 2008 the arsenic concentration varies from 1.44 ± 0.25 to 5.58 ± 0.55 ng/m³ with 95% confidence level (k = 2).

The association between arsenic exposure from drinking water and cerebrovascular disease mortality in Taiwan

BACKGROUND

Chronic arsenic exposure is associated with a variety of diseases, including cancer, peripheral vascular disease, and diabetes. However, its association with cerebrovascular diseases (CVD) has not yet been resolved. The aim of this study is to explore this association in Taiwan using nation-wide data.

MATERIALS AND METHODS

We analyzed mortality data in Taiwan from 1971 to 2005 and choose two geographic areas with populations suffering from chronic exposure to arsenic in drinking water for study, the blackfoot disease endemic area (BFDEA) in the southwest and Lan-Yang Basin (LYB) in the northeast parts of Taiwan. The Chia-Yi and Tainan Counties, which surround the BFDEA, and the nation of Taiwan as a whole were used as reference populations. Direct standardized mortality rates and gender-specific indirect standardized mortality ratios (SMRs) were calculated for the four populations.

RESULTS

The direct standardized mortality rate for CVD in Taiwan decreased from 2.46/10(3) person-year in 1971 to 0.63/10(3) person-year in 2005, and women had significantly lower mortality than men (SMR = 0.80; p < 0.05). The CVD mortality rates of populations with chronic arsenic exposure were significantly higher than the reference populations (SMR ranging from 1.06 to 1.09 in men and 1.12 to 1.14 in women; p < 0.05). The BFDEA had higher CVD mortality rates than the LYB, with SMR = 1.05 (p < 0.05) in men and SMR = 1.04 (p = 0.05) in women.

CONCLUSION

In Taiwan, while CVD mortality decreased in both genders between 1971 and 2005, chronic arsenic exposure from drinking water was associated with increased risks of CVD.