Showing papers in "Reviews on environmental health in 1999"

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

Abstract: 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.

Occupational exposure to ultraviolet radiation: a health risk assessment.

Abstract: This review applies health risk assessment methodology to the subject of occupational exposure to ultraviolet radiation (UVR). Ultraviolet radiation is produced by many sources, and for most people the sun is their main source of exposure. In the occupational environment, there are also many artificial sources, of which welding arcs are the predominant and most intense. Adverse health effects include photokeratitis, erythema, pterygium, some types of cataract, non-melanocytic skin cancer, and malignant melanoma. Outdoor workers and workers who are exposed to certain artificial sources (particularly welding arcs), frequently are exposed to UVR levels that are above the current exposure limits. Such workers may also be at an additional risk of developing nonmelanocytic skin cancer along with other chronic conditions, including malignant melanoma. A range of control measures is available but nevertheless, many workers (particularly those exposed to solar UVR) do not make full use of these measures. Therefore, the implementation of health education campaigns and other initiatives that encourage use are needed. Overall, although exposure to UVR presents a substantial risk for certain occupations, the current exposure standards and currently available control measures (if used) are considered to provide adequate protection for most workers.

Particulate air pollution and asthma: a review of epidemiological and biological studies.

Abstract: The link between exposure to air pollution and exacerbation of asthma symptoms has been investigated by epidemiological study and by direct biological experimentation. In asthmatics, epidemiological studies generally show a positive correlation between the particulate fraction of air pollution and increased morbidity, although roles for other co-pollutants (for example, ozone) are implicated as well. Direct experimentation using air pollutants, especially particles, to investigate their effects on humans or on animal models of asthma provides corroboration of the epidemiology and has begun to identify the pathophysiological mechanisms involved. We begin this review with an overview of air pollution, followed by a survey of the epidemiological and experimental data regarding air pollution particles and asthma. We finish with a discussion of directions for future research.

Urban health: an ecological perspective.

Abstract: At the Second European Conference on Environment and Health held in Helsinki in June 1994, urban health was attributed a high priority. This decision by the Ministers of Environment and Health from European countries reflects and reinforces a growing worldwide concern in the 1990s about the health status of residents of urban areas in all continents. The reasons for this concern include the rapid rate of urbanization and the increasing number of environmental, economic, and social problems, which have a negative impact on health and well-being in cities. This review presents a theoretical and methodological framework for the study of this vast and complex subject area. The paper proposes and illustrates an ecological perspective by discussing housing conditions and homelessness, as well as the concentration of poverty and deprivation in precise neighborhoods. To promote health and well-being more effectively, the ecological perspective presented in this paper can be applied by public health officers, by urban planners, and by policy decision-makers at national and local levels to promote our understanding of the multi-dimensional nature of health disorders of citizens. This approach should be a high priority for the beginning of the 21st century.

The gastrointestinal tract and acute effects of copper in drinking water and beverages.

Abstract: Copper is an essential element for all living beings. Exposure to copper results almost exclusively from the ingestion of food and water. Generally, potable water contains low levels of copper, but high concentrations of this mineral have been found in water from private wells or when water or beverages with low pH have been conducted through copper piping. Some authors have associated acute gastrointestinal symptoms (diarrhea, abdominal pain, nausea, and vomiting) with elevated levels of copper in water or beverages, but without excluding other confounding factors that could produce such symptoms. Recently, various controlled studies have demonstrated that a concentration of 2 mg Cu/L of potable water does not produce an increase in gastrointestinal symptoms in infants, and that in women, only concentrations greater than 3 mg Cu/L increase the number of episodes of nausea, vomiting, and abdominal pain, but not diarrhea. This critical analysis of scientific publications verifies the WHO provisional level for copper in drinking water (2 mg/L) as safe for human health.

Asbestos toxicity: an immunologic perspective.

Abstract: Asbestos has long been associated with a number of life threatening pulmonary diseases, including asbestosis and mesothelioma. While the lung is the primary target organ for asbestos toxicity, a number of clinical and experimental studies over the past 30 years have shown that the immune system may also be altered by exposure to asbestos at occupationally relevant concentrations. Whereas early clinical studies generally focused on systemic observations of immune alteration, more recent studies have assessed the immunological changes occurring in the lung, the primary target organ of asbestos. This review will focus on the investigations that examine the influence of asbestos on systemic and local immunity, as well as the role that the immune system may play in asbestos-related disease.

Pesticide exposure: human cancers on the horizon.

Abstract: Dichlorodiphenyltrichlorethane, a halogenated hydrocarbon, was introduced as an insecticide in the 1940s In her book "Silent Spring", Rachel Carson expressed her concern for the environment, plants, animals, and human health about the potential harmful effects of such chemicals In 1972, the Environmental Protection Agency banned the chemical in the USA DDT and its metabolite DDE are lipid soluble compounds that persist in the environment and bioaccumulate in the body in adipose tissue at levels far higher than those in blood and breast milk This paper evaluates the possibility of cancer occurring in humans from DDT exposure Some risk of lymphoma, leukemia, pancreatic cancer, and breast cancer was found in humans exposed to DDT Animal studies showed a significant association between DDT administration and lymphoma, respiratory cancer, liver cancer, and estrogenic effects on mammary tissue On the basis of on epidemiological principles, human studies were deficient in adequate sample sizes and were not exempt from such confounding factors as multiple chemical exposure, lifestyle factors, genetic, and other environmental influences Extrapolation of data on DDT toxicity from animals to humans has limitations With the persistence of DDT and DDE in the environment, the potential risk to the health of man, animals, and the environment remains

Bioaerosols in ambient air particulates: a review and research needs.

Abstract: Fine ( 10 microns Major pollen allergens have also been identified in size fractions smaller than that of intact pollen Special atmospheric conditions (such as rainfall) or interactions between air pollutants and pollen may produce allergenic fine particles Endotoxin (LPS), another important biological species of particles, may play a role in proinflammatory effects In this review, we discuss the possible interactions between pollen and pollutants and suggest several directions for future research

Social correlates of cigarette smoking cessation: findings from the 1995 microcensus survey in Germany.

Abstract: BACKGROUND An increasing percentage of smokers are quitting this unhealthy behavior during their life course. The aim of this study is to analyze which social factors play an important role regarding ex-smoking in Germany. METHODS Data were derived from the 1995 German Microcensus, which is a representative survey for the population in Germany. Included in the analysis were 44,553 current smokers and 23,780 ex-smokers. The independent variables were education, occupational status, family status, unemployment/social welfare, household income, and community size. A two-stage statistical modeling procedure was used, initially to assess the most important effects of the independent variables on smoking cessation and secondly, to analyze the cumulative effects of the independent variables. RESULTS The most striking effects observed for smoking cessation were family status and education. For example, in males aged 30 to 49 years, the percentages of ex-smokers of all ever smokers were 44.7% for married males with high education compared with only 14.6% for males with low education. The corresponding percentages for females were 44.0% and 17.6%. CONCLUSIONS Such striking differences in the social polarization of smoking cessation in Germany demonstrate the importance of anti-smoking policies and new strategies that avoid a further increase in the social inequality of smoking behavior.

Atmospheric carcinogens in Rio de Janeiro during the summer of 1998/99: benzo[a]pyrene and benzene.

Abstract: Rio de Janeiro, the second largest city in Brazil, is affected by severe pollution episodes and presents a high respiratory cancer incidence in comparison with the rest of the country. To monitor atmospheric pollution during the summer of 1998/1999 and to estimate the impact of organic pollution on public health, we determined the levels of two carcinogenic organic chemicals, benzo[a]pyrene and benzene, in four distinct sites throughout the city. A review of the levels recorded in other urban areas worldwide during the last ten years indicates that the benzo[a]pyrene (< or = 0.70 ng/m3) and benzene (< or = 11 micrograms/m3) concentrations found in Rio are relatively low. The highest levels were generally recorded in developing Asian countries, whereas the lowest values were found in North America. Unlike urban areas in temperate zones, pollution derived from domestic heating is minor in Rio de Janeiro, where most of the benzo[a]pyrene and benzene pollution originates from vehicular traffic. The quite distinct fuels used in light-duty vehicles in Brazil, combined with strong light incidence and increased rainfall during the summer, also contribute to diminish the levels of such pollutants.

Indoor allergen exposure in west and East Germany: a cause for different prevalences of asthma and atopy?

Abstract: West and East Germans have been living in two different political systems for 40 years. These two populations have become a classic epidemiological example for the hypothesis that lifestyle changes accompanying the industrial and economic development of modern societies are responsible for an increase in the prevalence of atopic diseases. A higher prevalence of atopic sensitization, asthma, and hay fever was found in young West Germans after the unification. It has been hypothesized that this phenomenon was at least partially due to the installation of insulating windows and central heating systems in Western homes, favoring the growth of microorganisms like mites and moulds and increasing indoor allergen exposure. This review summarizes studies that have investigated reservoir concentrations of indoor allergens in public buildings and private homes in East and West Germany. Whereas a higher prevalence of atopic sensitization in West Germans was found for nearly all tested allergens (cat, mite, pollen), allergen exposure was higher only for cat allergens, but probably not for mite and cockroach allergens or moulds. The published data do not support the view that the differences in specific sensitization are caused by differences in the exposure to specific allergens.

3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX): toxicological properties and risk assessment in drinking water.

Abstract: MX (3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone), one of the byproducts formed during the chlorine disinfection process of drinking water, shows strong mutagenic activity for Salmonella strains in the Ames test. In several countries, the contribution of MX to the total mutagenicity of drinking water is estimated to range from 7% to 67%. To assess the risk of MX for human health, we summarized the toxicological properties of MX and estimated the tolerable daily intake (TDI) or tolerable concentration in drinking water. MX is genotoxic in cultured mammalian cells and causes in vivo DNA damage in several tissues. MX is carcinogenic for rodents in addition to possessing skin and gastric promotion activities. From these toxicological profiles of MX, we estimated the virtual safety dose (VSD) for genotoxic action as 5 ng/kg/d and the TDI for non-genotoxic action of MX as 40 ng/kg/d. We assumed a tolerable MX concentration of 150 ng/L in drinking water. Because of the uncertainty about human genotoxicity, however, and the lack of information on reproductive or developmental toxicity, the estimated tolerable dose level may be provisional.

Inverse social gradient of secondary immune response parameters in children.

Abstract: BACKGROUND: In children, the prevalence of allergy increases with increasing socioeconomic status. If frequent immune response stimulation by infections protects against development of allergic diseases, then a social gradient in infections should exist. The aim of our study was to assess the relation between social class, immune parameters, and the prevalence of respiratory infections in children. METHODS: A cross-sectional survey examined children aged 5 to 14 years in 3 communities of Sachsen-Anhalt, Germany. Data of 1724 children were gathered by a parent-completed questionnaire and analyses of blood samples. Social class was defined by parental educational level. Immune parameters included serum immunoglobulin (Ig)G, IgA, and IgM; the C3c component of complement; and the total leukocyte count. The period prevalence of febrile colds and lifetime prevalences of physician-diagnosed bronchitis, tonsillitis, otitis media, and pneumonia were assessed from parents' reports. Adjusted odds ratios for the association between social class and belonging to the group of children with immune parameter levels in the upper 50th or 75th percentile or experiencing respiratory infections were calculated by logistic regression. RESULTS: Social class was inversely associated with secondary immune response parameters (IgG, IgA), whereas indicators of primary immune reactions and inflammation (IgM, C3c, leukocytes) were not related to social status. While an inverse social gradient was found for the period prevalence of febrile colds, the frequency of bronchitis, tonsillitis, and otitis media decreased with decreasing social class. CONCLUSIONS: Health inequalities exist in immune reactions and respiratory infections in children from different social classes. We hypothesize that in children from lower social classes, increased frequency of infections stimulated the secondary immune response and protected against more severe courses of respiratory infections.

Nutrition, nutritional habits, obesity, and prevalence of chronic diseases in workers.

Abstract: The purpose of the present investigation is to reveal the specifics of the nutrition, nutritional behavior (habits), the prevalence of obesity and of certain chronic diseases among workers. The subjects were 264 workers (203 males and 61 females) from the ammonium production department of a fertilizer plant, divided into two age groups: under and over 30 years of age. The data were collected by means of a food-frequency questionnaire about daily nutrition and the average quantity of food. The nutritional status was assessed on the basis of BMI. All workers underwent clinical examinations conducted by a range of different experts, including an internal diseases specialist, a neurologist, a cardiologist, an opthalmologist, an otorhino-laryngologist, and a dermatologist. Twenty hematological and biochemical indicators in blood and serum were measured. Assessment of the individual energy intake showed that hyperenergetic nutrition was typical of 67% of workers because of extra intake of fat, which was seen in 87.9% of all individuals examined. The daily fat intake of over 40E% was typical for almost half the females (45.9%). All age and gender groups displayed hyperprotein nutrition with pronounced cellulose (fiber) deficit and a high daily sodium intake. The frequency of overweight individuals (BMI = 25, 1-30 kg/m2) was 43.9%, whereas that of obese individuals (BMI = > 30 kg/m2) was 23.1%. A total of 67% of workers had excessive body mass. The hypertension prevalence rose significantly from 6.9% in Group I to 34.5% in Group II, and to 57.4% in Group III. Coronary heart disease was rare, but the seven cases registered were among the overweight workers. The radiculitis prevalence among workers with normal body mass was two-fold lower in comparison with both groups (overweight and obesity). We conclude that hyperenergetic and unbalanced nutrition is a factor that determines the prevalence of overweight and obesity. A significantly higher percent of overweight and obese workers suffered from hypertension, liver disease, diabetes, coronary heart disease, and eye-vessel diseases. A tendency toward rising radiculitis and musculoskeleton system disease prevalence was seen that parallels the increase in BMI.

Assessment of lead toxicity to the marine bacterium, Vibrio fischeri, and to a heterogeneous population of microorganisms derived from the Pearl River in Jackson, Mississippi, USA.

Abstract: Microorganisms are known to be excellent test organisms because of the relative ease for handling and suitability for analysis related to their small size, large number and convenient growing conditions. In this research, we tested the toxic effects of lead against a marine bacterium (Vibrio fischeri), and a heterogeneous population of bacteria derived from the Pearl River in Jackson, Mississippi. Using the level of bioluminescence in the Microtox Assay (V. fischeri), and the kinetics of dissolved oxygen uptake and growth (mixed bacterial population) as measures of toxicity, lead concentrations effecting a 50% reduction in these parameters (EC50) were determined as the toxic end-points. The activity quotients were also computed to determine the degrees of toxicity. Optical density (measure of growth) and oxygen uptake were measured over an extended period of time (20 h). EC50 values of 0.34 +/- 0.03, 3.10 +/- 0.01, and 3.80 +/- 0.02 mg/L were recorded for bioluminescence, growth, and oxygen uptake, respectively. As expected, the results indicated that the sensitivity to lead toxicity of V. fischeri was about one order of magnitude (10 times) greater than that of the mixed population of Pearl River microorganisms. Reductions in bioluminescence, growth, and oxygen uptake were directly correlated to lead concentrations, with toxic levels ranging from slightly toxic in lower concentrations to extremely toxic in higher concentrations. Upon 20 h of exposure, the times required to produce 50% reduction in dissolved oxygen uptake were (TD50S) 8.01 +/- 0.44, 9.60 +/- 0.46, 11.29 +/- 0.46, 13.03 +/- 0.57, 17.32 +/- 0.95, and 20.00 +/- 0.00 h in 0, 1, 2, 3, 4, 5, and 6 mg/L of lead, respectively, indicating a time-response relationship with respect to lead toxicity.

Complex interconvertibility of nitrogen oxides (NOX): impact on occupational and environmental health.

Abstract: Oxides of nitrogen have been implicated in a vast number of environmental and occupational health effects, some of which lack concrete mechanisms. Whereas certain compelling pieces of evidence link a particular nitrogen oxide to a particular adverse health effect, other reports seem to implicate virtually all the oxides in one form of toxic process or the other. Such diversity has probably emerged because each oxide of nitrogen possesses a different oxidation state, in which each form exerts different important levels of biological activity. Most important, each nitrogen oxide readily interconverts into another oxide at a very fast rate. This property of rapid interconvertibility poses problems to researchers in identifying with great confidence the actual oxide of nitrogen that is responsible for a specific occupational and environmental health effect. This paper reviews the complex nature of the nitrogen oxides (represented collectively as NOX) to explore the extent to which their acute or chronic exposure could be associated with toxicity. The nomenclature of the nitrogen oxides is outlined as a necessity for clarity and simplicity in understanding their reactions and interconvertibility and how they affect health. The natural occurrence and sources of occupational and environmental exposures and effects are critically evaluated and analyzed.

Allergy and the environment: a meeting report.

Abstract: 1. The widespread increase in allergy: a challenge for environmental medicine 2. Allergy from difference to disease 3. Immune mechanisms of allergic reactions 4. Selected environmental factors involved in allergy increase 4a. Infection and allergy 4b. The moving society 4c. The changing fats 4d. The case of aspirin 4e. Allergy and stress 5. Selected organ specificities of the allergic reactions 5a. The bronchi 5b. The nose 6. Conclusions and perspectives Abbreviations References

The Use of Epidemiological Data in the Control of Foodborne Viruses

Abstract: The Codex Committee on Food Hygiene has recommended the adoption of Hazard Analysis and Critical Control Point (HACCP) as the basis for food safety control. To provide an objective basis for the construction of HACCP systems, epidemiological data are required. The data should be accurate, up-to-date, and identify emerging pathogens, such as viruses. The number of laboratory reports of small, round-structured viruses in England and Wales has increased from 400 cases in 1990 to 2387 in 1996. Although a food vehicle is not essential for the spread of viral particles, food my be the primary unidentified vehicle. The Advisory Committee on the Microbiological Safety of Foods recommends the use of the Kaplan Criteria, which can give strong circumstantial evidence that an outbreak is attributable to small, round-structured viruses. The application of these criteria would give a more accurate reflection of the involvement of viruses in the incidence of foodborne disease. This review considers the use of epidemiological data to support HACCP and risk-assessment systems. It discusses the implications of focusing on traditional pathogens, for example Salmonella spp., as opposed to emerging pathogens, for the design of control systems. Recommendations are made for improving the system of data collection.

Manganese Retention in Rat Brain

Abstract: Manganese retention was observed in brains and in several other tissues of female Wistar rats after the intratracheal instillation of an inorganic manganese compound: manganese dioxide. Two categories of rats, younger (180 to 200g) and older (330 to 350g), were divided into a control group, in which animals received vehicle only (0.5 mL physiological saline), and an experimental group, in which rats received a dose of 0.48 mg of Mn/kg body weight (in 0.5 mL saline), twice a week for 3 months, for a total dosage of 11.80 mg of Mn/kg body weight. At the end of the exposure period, manganese retention in selected rat organs, brain, liver, kidney, and lung, was analyzed using atomic absorption spectrophotometry. At the end of the 6-wk or 12-wk manganese dioxide exposure period, analysis of variance of the manganese retention results revealed significant differences between Mn-exposed and unexposed rats in brain, kidney, and lung tissues (p<0.01) for both experimental age categories. Moreover, at the end of the 12-wk exposure period, significant results (p<0.05) between younger and older rats were obtained for both brain and kidneys. In both types of tissue, the manganese retention in the younger group was higher than that in older animals.

Climate change and its potential impacts on the Gulf Coast region of the United States.

Abstract: The Gulf Coast region of the United States abuts five states, including Alabama, Florida, Louisiana, Mississippi, and Texas. In general, the Gulf of Mexico has a surface area of 1.63 million square kilometers (630,000 square miles) and a watershed area of 4.69 million square kilometers (1.81 million square miles) in the United States. This region is one of the nation's largest ecological systems and is closely linked to a significant portion of the nation's economy. In the Gulf Coast region, energy, fisheries, agriculture, and tourism rank among the most significant sectors of the economy. The Gulf has five of the top ten fishing ports in the United States, and commercial fisheries in the Gulf annually produce nearly 2 billion tons of fish, oysters, shrimps, and crabs. Gulf ports handle one-half of the nation's import-export tonnage. Petroleum produced in the Gulf represents about 80% of the nation's offshore production. The Gulf Coast region largely relies on many natural resources to fuel many important sectors of its economy. But nevertheless, the health and vitality of the Gulf have declined in recent years, caused in part by increasing populations along its coast and the growing demand upon its resources and in part by the accumulation of years of careless depletion, abuse, and neglect of the environment. Equally important are the impacts of natural and human-induced climate change on the economy and on the quality of life for millions of people living in the Gulf Coast region. The results have generated alarming increases in damage to and destruction of the ecosystems and habitats of the Gulf. This paper reviews the nature of global environmental change and addresses the potential health and environmental impacts that may occur in the Gulf Coast region of the United States as a consequence of various environmental alterations resulting from global change.

Desert ecosystems: similarities, characteristics, and health benefits.

Abstract: Salty bodies of water in desert zones are known worldwide. The Salton Sea in California, USA, and the Dead Sea between Israel and Jordan are located in arid areas at approximately the same latitude, which might explain some similarities. Both the Salton and Dead Seas have ecosystems consisting of a singular saline sea/hot desert interface. The Salton Sea, the largest inland body of water in California, is a saline lake in the Coachella and Imperial Valleys. The Imperial Valley is one of the 10 top agricultural areas in the United States. Several thermoelectric plants exploiting geothermal wells operate around the Salton Sea, and some areas comprise a National Wildlife Refuge. The Dead Sea (Sea of Salt in Hebrew), the lowest saline lake on earth, contains high concentrations of salts and is a reservoir of minerals with a unique evaporation regime. The Dead Sea salts are the raw materials for the production of several chemical and health products. Magnesium salts and sulfur-containing mud are used for treating human skin disorders, allergies, arthritis, and respiratory diseases. After visiting both zones, we recorded, analyzed, and compared the similarities and differences between the areas. Some differences were found in the geographic, orographic, hydraulic, and climatic properties, but the main difference is in the economic-industrial aspect. The characteristics and health aspects are described in this report.