Prospective cohort study of respiratory effects at ages 14 to 26 following early life exposure to arsenic in drinking water.

BACKGROUND: We previously reported chronic respiratory effects in children who were then 7-17 years of age in Matlab, Bangladesh. One group of children had been exposed to high concentrations of arsenic in drinking water in utero and early childhood (average 436 µg/L), and the other group of children were never known to have been exposed to >10 µg/L. The exposed children, both males and females, had marked increases in chronic respiratory symptoms. METHODS: The current study involves a further follow-up of these children now 14-26 years of age with 463 located and agreeing to participate. They were interviewed for respiratory symptoms and lung function was measured. Data were collected on smoking, body mass index (BMI), and number of rooms in the house as a measure of socioeconomic status. RESULTS: Respiratory effects were still present in males but not females. In the high exposure group (>400 µg/L in early life) the odds ratio (OR) among male participants for dry cough in the last 12 months was 2.36 (95% confidence interval [CI] = 1.21, 4.63, P = 0.006) and for asthma OR = 2.51 (95% CI = 1.19, 5.29, P = 0.008). Forced vital capacity (FVC) was reduced in males in the early life high-exposure group compared with those never exposed (-95ml, P = 0.04), but not in female participants. CONCLUSIONS: By the age range 14-26, there was little remaining evidence of chronic respiratory effects in females but pronounced effects persisted in males. Mechanisms for the marked male female differences warrant further investigation along with further follow-up to see if respiratory effects continue in males.

Seasonal variation of arsenic concentrations in tubewells in west Bengal, India.

This study was conducted to monitor the changes in arsenic concentration during different seasons in a one-year period during 2002-2003 in selected tubewells in an arsenic-affected area in the district of South 24 Parganas in West Bengal, India, and to map the location of the wells. Seasonal variations in concentrations of arsenic in water were measured from 74 selected tubewells, ranging in depth from 40 to 500 feet. Water samples were collected from these wells during winter, summer, monsoon, and the following winter in 2002-2003. A global positioning system was used for locating the tubewells, and a geographic information system was used for mapping. There was evidence of seasonal variation in concentrations of arsenic in water (p=0.02) with the minimum average concentration occurring in the summer season (694 microg/L) and the maximum in the monsoon season (906 microg/L). From the winter of 2002 to the winter of 2003, arsenic concentrations increased, irrespective of the depth of the tubewells, from an average of 464 microg/L to 820 microg/L (p<0.001). This extent of variation in arsenic concentration, if confirmed, has important implications for both epidemiological research and mitigation programmes.

Capacity building in environmental health research in India and Nepal.

The Fogarty International Training and Research Program in Environmental and Occupational Health at UC Berkeley concentrates on two major environmental health issues in the Indian subcontinent: arsenic in drinking water in West Bengal, India, and indoor air pollution in India and Nepal. Local trainees and researchers have had the opportunity to work on related research. Concerning arsenic in drinking water, projects included studies of skin lesions, pulmonary effects, reproductive outcomes, and child development, as well as mitigation approaches to reduce exposures. Activities in the indoor air pollution project have emphasized quantifying exposures to smoke from cooking and heating as well as their associations with tuberculosis and eye disease. Training has focused on developing skills necessary to address these problems. The training emphasizes in-country mentoring of trainees related to their research projects, and intensive short courses at partner institutions. The focus of capacity building in environmental health research in countries in economic and environmental transition should be on country-based research projects with embedded training efforts.

Arsenic concentrations and bacterial contamination in a pilot shallow dugwell program in West Bengal, India.

Project Well has developed a pilot self-supporting community-based mitigation program to provide arsenic-safe water to the villagers of North 24 Parganas, West Bengal, India. Shallow concrete dugwells, less than 25 feet deep, that tap into an unconfined aquifer are constructed following stipulated guidelines. The design differs from the traditional dugwell in two major ways: (i) there is a layer of coarse sand in the annular space enveloping the outer wall of the concrete cylinder; and (ii) handpumps are used for water extraction to reduce the potential for bacterial contamination. Monitoring programs for arsenic and coliform bacteria in selected dugwells have been completed. In summer, when the water levels were low, the arsenic concentrations were measured. In 11 wells, measured over three years, the average water arsenic concentration was 29 micro gL-1. Two dugwells had high concentrations of arsenic (average 152 micro gL-1 and 61 micro gL-1), but the remaining nine dugwells had an overall average of 11 micro gL-1. Seasonal variation was assessed in five wells with monthly measurements and there was a direct relationship between increases in arsenic concentrations and decreases in the volume of water in the dugwells in the dry summer season. To control bacterial contamination, sodium hypochlorite solution containing 5% chlorine was applied once a month. In 2005, fecal coliform was undetected in 65% (n = 13) of the dugwells but detected at high levels in 35% (n = 7) of the dugwells. The program clearly reduced exposure to arsenic, but we conclude that further study of increases in arsenic concentrations in the dry season are warranted, as well as assessment of ways to more effectively control bacterial contamination such as more frequent chlorination, perhaps with lower doses on each occasion.

Children's intellectual function in relation to arsenic exposure.

BACKGROUND: Very little evidence exists concerning the possible impairment of children's intellectual function in relation to arsenic exposure in utero and during childhood. METHODS: We conducted a cross-sectional study among 351 children age 5 to 15 years who were selected from a source population of 7683 people in West Bengal, India, in 2001-2003. Intellectual function was assessed with 6 subtests from the Wechsler Intelligence Scale for Children as well as with the Total Sentence Recall test, the Colored Progressive Matrices test, and a pegboard test. Arsenic in urine and lifetime water sources (including during the pregnancy period) were assessed using measurements of samples from 409 wells. The test scores were analyzed with linear regression analyses based on the method of generalized estimating equations incorporating relevant covariates. RESULTS: Stratifying urinary arsenic concentrations into tertiles, we found associations between arsenic and reductions in the adjusted scores of the vocabulary test (0, -0.14, -0.28; P for trend = 0.02), the object assembly test (0, -0.16, -0.24; P for trend = 0.03), and the picture completion test (0, -0.15, -0.26; P for trend = 0.02). These findings correspond to relative declines of 12% (95% confidence interval =0.4% to 24%) in the vocabulary test, 21% (-0.8% to 42%) in the object assembly test, and of 13% (0.3% to 24%) in the picture completion test in the upper urinary arsenic tertile. However, we did not find evidence of an association between test results and arsenic water concentrations during pregnancy or childhood. CONCLUSIONS: Current arsenic concentrations in urine, which reflect all sources of recent exposure, including water and food, were associated with small decrements in intellectual testing in school-aged children in West Bengal. We did not see associations between long-term water arsenic concentrations and intellectual function.

Blood concentrations of methionine, selenium, beta-carotene, and other micronutrients in a case-control study of arsenic-induced skin lesions in West Bengal, India.

Previous studies have suggested that susceptibility to arsenic toxicity could be influenced by micronutrients, in particular selenium, methionine, and beta-carotene. A case-control study was conducted in West Bengal, India, in a region known to have groundwater arsenic contamination, to determine whether differences in micronutrient status contribute to susceptibility to arsenic-induced skin lesions. Micronutrient status was assessed by blood levels of specific micronutrients and metabolic indicators. Blood was obtained from 180 cases with skin lesions and 192 controls. Blood assays measured micronutrients and carotenoids (folate, selenium, vitamin B12, vitamin B6, retinol, alpha-tocopherol, lutein/zeaxanthin, beta-carotene, lycopene, beta-cryptoxanthin) and metabolic indicators such as glucose, cholesterol, transthyretin, amino acids, and proteins potentially associated with methylation (cysteine, homocysteine, methionine, glutathione). The distributions of nutrient concentrations were similar in cases and controls. The median selenium concentrations in cases and controls were both 1.15 micromol/L, and there was little evidence of differences in other micronutrients. Odds ratios (ORs) for arsenic-induced skin lesions were estimated for each quartile of nutrient concentrations, using the quartile with the highest nutrient level as the referent group. There were no clear trends associated with deficiencies of any micronutrient or metabolic indicator. For decreasing quartiles of selenium, the OR estimates were 1.00, 0.67, 0.99, 0.80; P=0.81; for methionine, the OR estimates were 1.00, 0.83, 0.78, 0.72; P=0.29. For beta-carotene, the ORs were 1.00, 0.53, 0.51, 0.96, demonstrating no increased risk at the lower quartiles. The measured micronutrients and metabolic indicators investigated do not appear to modify the risk of developing arsenic-induced skin lesions. The lack of any trend of increasing risk with lower selenium, vitamin E, and beta-carotene concentrations has important implications for proposed therapeutic interventions. The emphasis of interventions should be on reducing arsenic exposure.

Bronchiectasis in persons with skin lesions resulting from arsenic in drinking water.

BACKGROUND: Arsenic is a unique human carcinogen in that it causes lung cancer by exposure through ingestion (in drinking water) as well as through inhalation. Less is known about nonmalignant pulmonary disease after exposure to arsenic in drinking water. METHODS: We recruited 108 subjects with arsenic-caused skin lesions and 150 subjects without lesions from a population survey of over 7000 people in an arsenic-exposed region in West Bengal, India. Thirty-eight study participants who reported at least 2 years of chronic cough underwent high-resolution computed tomography (CT); these scans were read by investigators in India and the United States without knowledge of the presence or absence of skin lesions. RESULTS: The mean (+/-standard deviation) bronchiectasis severity score was 3.4 (+/-3.6) in the 27 participants with skin lesions and 0.9 (+/-1.6) in the 11 participants without these lesions. In subjects who reported chronic cough, CT evidence of bronchiectasis was found in 18 (67%) participants with skin lesions and 3 (27%) subjects without skin lesions. Overall, subjects with arsenic-caused skin lesions had a 10-fold increased prevalence of bronchiectasis compared with subjects who did not have skin lesions (adjusted odds ratio=10; 95% confidence interval=2.7-37). CONCLUSIONS: These results suggest that, in addition to being a cause of lung cancer, ingestion of high concentrations of arsenic in drinking water may be a cause of bronchiectasis.

Decrements in lung function related to arsenic in drinking water in West Bengal, India.

During 1998-2000, the authors investigated relations between lung function, respiratory symptoms, and arsenic in drinking water among 287 study participants, including 132 with arsenic-caused skin lesions, in West Bengal, India. The source population involved 7,683 participants who had been surveyed for arsenic-related skin lesions in 1995-1996. Respiratory symptoms were increased among men with arsenic-caused skin lesions (versus those without lesions), particularly "shortness of breath at night" (odds ratio (OR) = 2.8, 95% confidence interval (CI): 1.1, 7.6) and "morning cough" (OR = 2.8, 95% CI: 1.2, 6.6) in smokers and "shortness of breath ever" (OR = 3.8, 95% CI: 0.7, 20.6) in nonsmokers. Among men with skin lesions, the average adjusted forced expiratory volume in 1 second (FEV1) was reduced by 256.2 ml (95% CI: 113.9, 398.4; p < 0.001) and the average adjusted forced vital capacity (FVC) was reduced by 287.8 ml (95% CI: 134.9, 440.8; p < 0.001). In men, a 100-microg/liter increase in arsenic level was associated with a 45.0-ml decrease (95% CI: 6.2, 83.9) in FEV1 (p = 0.02) and a 41.4-ml decrease (95% CI: -0.7, 83.5) in FVC (p = 0.054). Women had lower risks than men of developing skin lesions and showed little evidence of respiratory effects. In this study, consumption of arsenic-contaminated water was associated with respiratory symptoms and reduced lung function in men, especially among those with arsenic-related skin lesions.