Arsenic geochemistry and human health in South East Asia

Arsenic occurs naturally in many environmental components and enters the human body through several exposure pathways. Natural enrichment of arsenic may result in considerable contamination of soil, water, and air. Arsenic in groundwater can exceed values hundreds of time higher than the concentration recommended for drinking water. Such exposure levels indicate a serious potential health risk to individuals consuming raw groundwater. Human activities that have an impact on the environment may increase the distribution of inorganic arsenic. Abandoned mines are of great concern due to the extremely high arsenic concentrations detected in mine drainage and tailings. Diet, drinking water, air, soil, and occupational exposures are all sources of inorganic arsenic for humans. Interdisciplinary efforts to better characterize the transport of arsenic and reactants that facilitate their release to the environment are important for human health studies. Multi-disciplinary efforts are needed to study diet, infectious disease, genetics, and cultural practices unique to each region to better understand human health risk and to design public health interventions.     

Environmental risks to public health in the United Arab Emirates: a quantitative assessment and strategic plan

Background: Environmental risks to health in the United Arab Emirates (UAE) have shifted rapidly from infectious to noninfectious diseases as the nation has developed at an unprecedented rate. In response to public concerns over newly emerging environmental risks, the Environment Agency–Abu Dhabi commissioned a multidisciplinary environmental health strategic planning project.Objectives: In order to develop the environmental health strategic plan, we sought to quantify the illnesses and premature deaths in the UAE attributable to 14 environmental pollutant categories, prioritize these 14 risk factors, and identify interventions.Methods: We estimated the disease burden imposed by each risk factor using an attributable fraction approach, and we prioritized the risks using an empirically tested stakeholder engagement process. We then engaged government personnel, scientists, and other stakeholders to identify interventions.Results: The UAE’s environmental disease burden is low by global standards. Ambient air pollution is the leading contributor to premature mortality [~ 650 annual deaths; 95% confidence interval (CI): 140, 1,400]. Risk factors leading to > 10,000 annual health care facility visits included occupational exposures, indoor air pollution, drinking water contamination, seafood contamination, and ambient air pollution. Among the 14 risks considered, on average, outdoor air pollution was ranked by the stakeholders as the highest priority (mean rank, 1.4; interquartile range, 1–2) and indoor air pollution as the second-highest priority (mean rank 3.3; interquartile range, 2–4). The resulting strategic plan identified 216 potential interventions for reducing environmental risks to health.Conclusions: The strategic planning exercise described here provides a framework for systematically deciding how to invest public funds to maximize expected returns in environmental health, where returns are measured in terms of reductions in a population’s environmental burden of disease.     

Chronic arsenic poisoning from burning high-arsenic-containing coal in Guizhou, China

Arsenic is an environmental hazard and the reduction of drinking water arsenic levels is under consideration. People are exposed to arsenic not only through drinking water but also through arsenic-contaminated air and food. Here we report the health effects of arsenic exposure from burning high arsenic-containing coal in Guizhou, China. Coal in this region has undergone mineralization and thus produces high concentrations of arsenic. Coal is burned inside the home in open pits for daily cooking and crop drying, producing a high concentration of arsenic in indoor air. Arsenic in the air coats and permeates food being dried producing high concentrations in food; however, arsenic concentrations in the drinking water are in the normal range. The estimated sources of total arsenic exposure in this area are from arsenic-contaminated food (50-80%), air (10-20%), water (1-5%), and direct contact in coal-mining workers (1%). At least 3,000 patients with arsenic poisoning were found in the Southwest Prefecture of Guizhou, and approximately 200,000 people are at risk for such overexposures. Skin lesions are common, including keratosis of the hands and feet, pigmentation on the trunk, skin ulceration, and skin cancers. Toxicities to internal organs, including lung dysfunction, neuropathy, and nephrotoxicity, are clinically evident. The prevalence of hepatomegaly was 20%, and cirrhosis, ascites, and liver cancer are the most serious outcomes of arsenic poisoning. The Chinese government and international organizations are attempting to improve the house conditions and the coal source, and thereby protect human health in this area.     

Bilateral environmental and occupational health program with India

In spite of considerable economic progress in recent years, India continues to face challenges dealing with poverty, unemployment, malnutrition, disease and disability. The governments of India and the United States have formed a collaborative effort to address outstanding issues in the fields of environmental and occupational health. The Joint Statement on Indo-U.S. Collaboration in Environmental and Occupational Health, which was approved by the Minister of the Indian Union of Health and Family Welfare and the Secretary of Health and Human Services of the United State in Geneva in May of 2002, formalizes the collaborative relationship and calls for the development of Implementation Guidelines. The Implementation Guidelines establish a Joint Working Group, which is responsible for identifying and implementing the collaborative projects. The collaborating organizations have identified three broad areas for collaboration: emergency preparedness and response; training, education, and technology transfer; and research. Within the three broad areas, the organizations have identified two subject areas for initiation: arsenicosis and asbestosis. Researchers and health officials in both India and the U.S. share interest in both research and interventions efforts in these subject areas. As many as 42 million people in the West Bengal area of India may be exposed to arsenic in drinking water at concentrations of health concern. Similarly, as many as 10 million industrial or mine workers in India may be exposed to asbestos or other dusts at concentrations of health concern. The first Joint Working Group meeting is scheduled for March 2003 in New Delhi and will consider these subject areas in developing collaborative projects. Other tasks being undertaken by the signatory agencies include expanding the relationship to include academic and nongovernmental organizations and obtaining funds for the various projects from governmental and nongovernmental sources.     

Environmental Source of Arsenic Exposure

Arsenic is a ubiquitous, naturally occurring metalloid that may be a significant risk factor for cancer after exposure to contaminated drinking water, cigarettes, foods, industry, occupational environment, and air. Among the various routes of arsenic exposure, drinking water is the largest source of arsenic poisoning worldwide. Arsenic exposure from ingested foods usually comes from food crops grown in arsenic-contaminated soil and/or irrigated with arsenic-contaminated water. According to a recent World Health Organization report, arsenic from contaminated water can be quickly and easily absorbed and depending on its metabolic form, may adversely affect human health. Recently, the US Food and Drug Administration regulations for metals found in cosmetics to protect consumers against contaminations deemed deleterious to health; some cosmetics were found to contain a variety of chemicals including heavy metals, which are sometimes used as preservatives. Moreover, developing countries tend to have a growing number of industrial factories that unfortunately, harm the environment, especially in cities where industrial and vehicle emissions, as well as household activities, cause serious air pollution. Air is also an important source of arsenic exposure in areas with industrial activity. The presence of arsenic in airborne particulate matter is considered a risk for certain diseases. Taken together, various potential pathways of arsenic exposure seem to affect humans adversely, and future efforts to reduce arsenic exposure caused by environmental factors should be made.     

Hair and toenail arsenic concentrations of residents living in areas with high environmental arsenic concentrations

Surface soil and groundwater in Australia have been found to contain high concentrations of arsenic. The relative importance of long-term human exposure to these sources has not been established. Several studies have investigated long-term exposure to environmental arsenic concentrations using hair and toenails as the measure of exposure. Few have compared the difference in these measures of environmental sources of exposure. In this study we aimed to investigate risk factors for elevated hair and toenail arsenic concentrations in populations exposed to a range of environmental arsenic concentrations in both drinking water and soil as well as in a control population with low arsenic concentrations in both drinking water and soil. In this study, we recruited 153 participants from areas with elevated arsenic concentrations in drinking water and residential soil, as well as a control population with no anticipated arsenic exposures. The median drinking water arsenic concentrations in the exposed population were 43.8 micro g/L (range, 16.0-73 micro g/L) and median soil arsenic concentrations were 92.0 mg/kg (range, 9.1-9,900 mg/kg). In the control group, the median drinking water arsenic concentration was below the limit of detection, and the median soil arsenic concentration was 3.3 mg/kg. Participants were categorized based on household drinking water and residential soil arsenic concentrations. The geometric mean hair arsenic concentrations were 5.52 mg/kg for the drinking water exposure group and 3.31 mg/kg for the soil exposure group. The geometric mean toenail arsenic concentrations were 21.7 mg/kg for the drinking water exposure group and 32.1 mg/kg for the high-soil exposure group. Toenail arsenic concentrations were more strongly correlated with both drinking water and soil arsenic concentrations; however, there is a strong likelihood of significant external contamination. Measures of residential exposure were better predictors of hair and toenail arsenic concentrations than were local environmental concentrations.     

An aggregate public health indicator to represent the impact of multiple environmental exposures.

We present a framework to aggregate divergent health impacts associated with different types of environmental exposures, such as air pollution, residential noise, and large technologic risks. From the policy maker's point of view, there are at least three good reasons for this type of aggregation: comparative risk evaluation (for example, setting priorities), evaluation of the efficiency of environmental policies in terms of health gain, and characterizing health risk associated with geographical accumulation of multiple environmental exposures. The proposed impact measure integrates three important dimensions of public health: life expectancy, quality of life, and number of people affected. Time is the unit of measurement. "Healthy life years" are either lost by premature death or by loss of quality of life, measured as discounted life years within a population. Severity weights (0 for perfect health, 1 for death) are assigned to discount the time spent with conditions associated with environmental exposures. We combined information on population exposure distribution, exposure response relations, incidence, and prevalence rates to estimate annual numbers of people affected and the duration of the condition, including premature death. Using data from the fourth Dutch National Environmental Outlook, we estimated that the long-term effects of particulate air pollution account for almost 60% of the total environment-related health loss in the Netherlands as modeled here. Environmental noise accounts for 24%, indoor air pollution (environmental tobacco smoke, radon, and dampness, as well as lead in drinking water) for around 6%, and food poisoning (or infection) for more than 3%. The contribution of this set of environmental exposures to the total annual burden of disease in the Netherlands is less than 5%.     

An estimation of the global burden of disease due to skin lesions caused by arsenic in drinking water

The global burden of disease due to skin lesions caused by arsenic in drinking water was estimated by combining country-based exposure data with selected exposure-response relationships derived from the literature. Populations were considered to be exposed to elevated arsenic levels if their drinking water contained arsenic concentrations of 50 microg I(-1) or greater. Elevated arsenic concentrations in drinking water result in a significant global burden of disease, even when confining the health outcome to skin lesions. The burden of disease was particularly marked in the World Health Organization (WHO) comparative risk assessment (CRA) 'Sear D' region, which includes Bangladesh, India and Nepal. Unsurprisingly, Bangladesh was the worst affected country with 143 disability adjusted life years (DALYs) per 1,000 population. Although this initial estimate is subject to a large degree of uncertainty, it does represent an important first step in allowing the comparison of the problem relating to elevated arsenic in drinking water to other environmental health outcomes.     

Paradigms and progress in building research capacity in international environmental health

Populations in low- and middle-income nations bear significant risks for poor health due to air, land and water contamination; natural resource depletion; deterioration of ecosystems; contaminated food supplies and other conditions related to poverty, including poor housing, crowding and inadequate nutrition and health care. These risks, related to rapid industrialization, increasing urbanization, poor land use, natural changes in ecology and other conditions, will only increase in the coming decades if current trends persist. The implications on populations' health include increased spread or emergence of disease, particularly those that impact children disproportionately, and added stress on already overburdened or weakened health care systems. To address environmental health conditions in a relevant manner in resource-poor settings, the training of scientists and health professionals from these settings is key to setting priorities and identifying cost-effective interventions. Training of professionals in a range of environmental health disciplines is a prerequisite for the establishment of effective national and international policies. Working to strengthen local expertise and scientific capacity is one of the most effective and lasting ways to affect positive policy change in environmental health. This paper describes four paradigms that support research training and research programs to meet the increasing and changing needs in this field. Factors influencing the development of the programs and their evolution are discussed as well as trends for the future.     

Important considerations in the development of public health advisories for arsenic and arsenic-containing compounds in drinking water

Drinking water contamination by arsenic remains a major public health problem. Acute and chronic arsenic exposure via drinking water has been reported in many countries of the world; especially in Argentina, Bangladesh, India, Mexico, Thailand, and Taiwan, where a large proportion of drinking water (ground water) is contaminated with a high concentration of arsenic. Research has also pointed out significantly higher standardized mortality ratios and cumulative mortality rates for cancers of the bladder, kidney, skin, liver, and colon in many areas of arsenic pollution. General health effects that are associated with arsenic exposure include cardiovascular and peripheral vascular disease, developmental anomalies, neurologic and neurobehavioral disorders, diabetes, hearing loss, portal fibrosis of the liver, lung fibrosis, hematologic disorders (anemia, leukopenia, and eosinophilia), and carcinoma. Although, the clinical manifestations of arsenic poisoning appear similar, the toxicity of arsenic compounds depends largely u[on the chemical species and the form of arsenic involved. On the basis of its high degree of toxicity to humans, and the non-threshold dose-response assumption, a zero level exposure is recommended for arsenic, even though this level is practically non-attainable. In this review, we provide and discuss important information on the physical and chemical properties, production and use, fate and transport, toxicokinetics, systemic and carcinogenic health effects, regulatory and health guidelines, analytical methods, and treatment technologies that are applied to arsenic pollution. Such information is critical in assisting the federal, state and local officials who are responsible for protecting public health in dealing with the problem of drinking water contamination by arsenic and arsenic-containing compounds.     

Public health engineering education in India: current scenario, opportunities and challenges

Public health engineering can play an important and significant role in solving environmental health issues. In order to confront public health challenges emerging out of environmental problems we need adequately trained public health engineers / environmental engineers. Considering the current burden of disease attributable to environmental factors and expansion in scope of applications of public health / environmental engineering science, it is essential to understand the present scenario of teaching, training and capacity building programs in these areas. Against this background the present research was carried out to know the current teaching and training programs in public health engineering and related disciplines in India and to understand the potential opportunities and challenges available. A systematic, predefined approach was used to collect and assemble the data related to various teaching and training programs in public health engineering / environmental engineering in India. Public health engineering / environmental engineering education and training in the country is mainly offered through engineering institutions, as pre-service and in-service training. Pre-service programs include diploma, degree (graduate) and post-graduate courses affiliated to various state technical boards, institutes and universities, whereas in-service training is mainly provided by Government of India recognized engineering and public health training institutes. Though trainees of these programs acquire skills related to engineering sciences, they significantly lack in public health skills. The teaching and training of public health engineering / environmental engineering is limited as a part of public health programs (MD Community Medicine, MPH, DPH) in India. There is need for developing teaching and training of public health engineering or environmental engineering as an interdisciplinary subject. Public health institutes can play an important and significant role in this regard by engaging themselves in initiating specialized programs in this domain.     

室内空气污染与人体健康关系研究进展

该文对近20年来室内空气污染与人体健康关系研究领域的进展进行了评述,着重讨论了环境污染危险度评价方法的研究,室内空气污染所致的重大健康影响,室内空气污染所致的轻微、有限的健康影响以及其他需要重点关注的问题。     

A Framework for Examining Social Stress and Susceptibility to Air Pollution in Respiratory Health

Objective

There is growing interest in disentangling the health effects of spatially clustered social and physical environmental exposures and in exploring potential synergies among them, with particular attention directed to the combined effects of psychosocial stress and air pollution. Both exposures may be elevated in lower-income urban communities, and it has been hypothesized that stress, which can influence immune function and susceptibility, may potentiate the effects of air pollution in respiratory disease onset and exacerbation. In this paper, we attempt to synthesize the relevant research from social and environmental epidemiology, toxicology, immunology, and exposure assessment to provide a useful framework for environmental health researchers aiming to investigate the health effects of environmental pollution in combination with social or psychological factors.

Data synthesis

We review the existing epidemiologic and toxicologic evidence on synergistic effects of stress and pollution, and then describe the physiologic effects of stress and key issues related to measuring and evaluating stress as it relates to physical environmental exposures and susceptibility. Finally, we identify some of the major methodologic challenges ahead as we work toward disentangling the health effects of clustered social and physical exposures and accurately describing the interplay among these exposures.

Conclusions

There is still tremendous work to be done toward understanding the combined and potentially synergistic health effects of stress and pollution. As this research proceeds, we recommend careful attention to the relative temporalities of stress and pollution exposures, to nonlinearities in their independent and combined effects, to physiologic pathways not elucidated by epidemiologic methods, and to the relative spatial distributions of social and physical exposures at multiple geographic scales.     

陕西镇巴双河村燃煤型地方性砷中毒流行现状调查

目的:了解双河村地方性砷中毒流行现状,为防治研究提供科学依据。方法:选择双河村常住人口且年龄在6周岁以上人群作为调查对象;同时,另选一个没有砷污染的旬邑县作为对照。采集与双河村居民生活密切相关的饮用水、土壤、玉米、辣椒、室内空气、石煤以及部分居民的头发和尿液样品,测定砷含量。同时,对该村常住居民进行地方性砷中毒临床检查和流行病学调查。结果:调查结果显示,除水和土壤砷含量远低于国家标准外,石煤、发砷和尿砷含量均全部超标,室内空气、玉米、辣椒中的砷含量也不同程度的超标,且部分样品超标严重。地方性砷中毒临床诊断结果显示,该村患病率高达31.60%。结论:双河村已经成为燃煤型地方性砷中毒发病较重的村。     

Arsenic exposure from drinking water and birth weight

BACKGROUND: Arsenic exposures from drinking water increase the risk of various cancers and noncancer health endpoints. Limited evidence suggests that arsenic may have adverse human reproductive effects. We investigated the association between drinking water arsenic exposure and fetal growth, as manifest in birth weight. METHODS: We conducted a prospective cohort study in two Chilean cities with contrasting drinking water arsenic levels: Antofagasta (40 micro g/L) and Valparaíso (<1 micro g/L). Study subjects completed in-depth interviews and provided urine samples for exposure analysis. We obtained pregnancy and birth information from medical records. The birth weight analysis was restricted to liveborn, singleton infants born between December 1998 and February 2000. RESULTS: The final study group consisted of 424 infants from Antofagasta and 420 from Valparaíso. After controlling for confounders, results of the multivariable analysis indicated that Antofagasta infants had lower mean birth weight (-57 g; 95% confidence interval = -123 to 9). CONCLUSION: This study suggests that moderate arsenic exposures from drinking water (<50 micro g/L) during pregnancy are associated with reduction in birth weight, similar in magnitude to that resulting from other environmental exposures such as environmental tobacco smoke and benzene.     

Case studies--arsenic

Arsenic is found naturally in the environment. People may be exposed to arsenic by eating food, drinking water, breathing air, or by skin contact with soil or water that contains arsenic. In the U.S., the diet is a predominant source of exposure for the general population with smaller amounts coming from drinking water and air. Children may also be exposed to arsenic because of hand to mouth contact or eating dirt. In addition to the normal levels of arsenic in air, water, soil, and food, people could by exposed to higher levels in several ways such as in areas containing unusually high natural levels of arsenic in rocks which can lead to unusually high levels of arsenic in soil or water. People living in an area like this could take in elevated amounts of arsenic in drinking water. Workers in an occupation that involves arsenic production or use (for example, copper or lead smelting, wood treatment, pesticide application) could be exposed to elevated levels of arsenic at work. People who saw or sand arsenic-treated wood could inhale/ingest some of the sawdust which contains high levels of arsenic. Similarly, when pressure-treated wood is burned, high levels of arsenic could be released in the smoke. In agricultural areas where arsenic pesticides were used on crops the soil could contain high levels of arsenic. Some hazardous waste sites contain large quantities of arsenic. Arsenic ranks #1 on the ATSDR/EPA priority list of hazardous substances. Arsenic has been found in at least 1,014 current or former NPL sites. At the hazardous waster sites evaluated by ATSDR, exposure to arsenic in soil predominated over exposure to water, and no exposure to air had been recorded. However, there is no information on morbidity or mortality from exposure to arsenic in soil at hazardous waste sites. Exposure assessment, community and tribal involvement, and evaluation and surveillance of health effects are among the ATSDR future Superfund research program priority focus areas. Examples of exposures to arsenic in drinking water, diet and pesticide are given.     

Nonoccupational exposures to indoor air pollutants: a survey of state programs and practices

A national survey of health department activities in 1982 revealed that 32 states (63 per cent) had a program or person(s) responsible for evaluating exposures to one or more nonoccupational indoor air pollutants (NIAPs). Only four states (8 per cent) had existing or proposed NIAP exposure standards. Twenty-nine (57 per cent) of the states had a program to evaluate nonoccupational exposures to formaldehyde, but these varied widely. There is a need for coordinated, consistent approaches to defining and controlling emerging environmental public health problems such as indoor air pollution.     

Understanding the link between environmental exposures and health: does the exposome promise too much?

Environmental exposures affecting human health range from complex mixtures, such as environmental tobacco smoke, ambient particulate matter air pollution and chlorination by products in drinking water, to hazardous chemicals, such as lead, and polycyclic aromatic hydrocarbons, such as benz(a)pyrene. The exposome has been proposed to complement the genome and be the totality of all environmental exposures of an individual over his or her lifetime. However, if measurements of the exposome in biological samples are the sole tool for exposure assessment there are a number of limitations. First, it has limited utility for fully capturing the impact of complex mixtures such environmental tobacco smoke or particulate matter air pollution. Second, a number of relevant environmental exposures such as noise, heat or electromagnetic fields do not have direct correlates as metabolites or protein adducts, but there is important evidence linking them with health effects. Third, functional genomic changes are likely in many instances to be both a susceptibility factor and a marker of internal doses in response to environmental exposures. Fourth, internal dose measurements of environmental exposures might have lost the distinct signature of the relevant sources. This paper emphasises the obligation of environmental epidemiology to provide robust evidence to assist timely and sufficient protection of vulnerable subgroups of populations from environmental hazards. Therefore, in applying the exposome concept to environmental health problems, a strong link with the external environment needs to be maintained.     

Inference for environmental intervention studies using principal stratification

Previous research has found evidence of an association between indoor air pollution and asthma morbidity in children. Environmental intervention studies have been performed to examine the role of household environmental interventions in altering indoor air pollution concentrations and improving health. Previous environmental intervention studies have found only modest effects on health outcomes and it is unclear if the health benefits provided by environmental modification are comparable with those provided by medication. Traditionally, the statistical analysis of environmental intervention studies has involved performing two intention‐to‐treat analyses that separately estimate the effect of the environmental intervention on health and the effect of the environmental intervention on indoor air pollution concentrations. We propose a principal stratification approach to examine the extent to which an environmental intervention's effect on health outcomes coincides with its effect on indoor air pollution. We apply this approach to data from a randomized air cleaner intervention trial conducted in a population of asthmatic children living in Baltimore, Maryland, USA. We find that among children for whom the air cleaner reduced indoor particulate matter concentrations, the intervention resulted in a meaningful improvement of asthma symptoms with an effect generally larger than previous studies have shown. A key benefit of using principal stratification in environmental intervention studies is that it allows investigators to estimate causal effects of the intervention for sub‐groups defined by changes in the indoor air pollution concentration. Copyright © 2014 John Wiley & Sons, Ltd.     

中国地方性砷中毒分布调查(总报告)

为查清我国地方性砷中毒的基本分布 ,指导和推进我国的地方性砷中毒的防治工作 ,采用环境流行病学调查方法 ,包括回顾性环境流行病学调查 ,重点病区调查和面上抽样调查 ,搜集掌握病情资料。采用环境化学标准方法与质量控制分析环境砷水平 ,回顾性调查中利用己有的环境砷资料 ,重点调查与面上抽样现况调查中检测环境砷含量。最后对二者结果进行计算机统计分析。饮水型地方性砷中毒分布于 8省市区 ,40个县旗市 ,受影响人口 2 3 4 3 2 3 8人 ,其中饮水砷 >0 .0 5mg L高砷暴露人口 52 2 566人 ,查出砷中毒 782 1人。内蒙、山西仍为我国饮水型地方性砷中毒重病区 ,新疆乌苏市的生产建设兵团与乌苏中的大部分高砷地区集中改水 ,病情减轻。内蒙、山西的一些乡村集中改水降砷效果较好。新确认吉林、宁夏各 1县饮水型地方性砷中毒 ,其中以吉林省病区为典型。新发现山西 11县市、内蒙 1旗、吉林 1市、宁夏 1县、青海 1县和安徽 2县市的饮水型地方性砷中毒。新发现北京顺义区仍有饮水高砷暴露乡镇。未发现其它省、市、自治区有饮水高砷暴露地区。确认辽宁省曾报道的饮水高砷点现已消除 ;浙江桐乡市已有的饮水高砷地区现已降至饮水砷卫生标准以下 ;并发现北京市顺义区天竺乡天竺村连续 2 0余年的饮水高砷井自然转变?