Climate change, noncommunicable diseases, and development: the relationships and common policy opportunities.

The rapid growth in noncommunicable diseases (NCDs), including injury and poor mental health, in low- and middle-income countries and the widening social gradients in NCDs within most countries worldwide pose major challenges to health and social systems and to development more generally. As Earth's surface temperature rises, a consequence of human-induced climate change, incidences of severe heat waves, droughts, storms, and floods will increase and become more severe. These changes will bring heightened risks to human survival and will likely exacerbate the incidence of some NCDs, including cardiovascular disease, some cancers, respiratory health, mental disorders, injuries, and malnutrition. These two great and urgent contemporary human challenges-to improve global health, especially the control of NCDs, and to protect people from the effects of climate change-would benefit from alignment of their policy agendas, offering synergistic opportunities to improve population and planetary health. Well-designed climate change policy can reduce the incidence of major NCDs in local populations.

Urban planning and public health at CDC.

Urban planning, also called city and regional planning, is a multidisciplinary field in which professionals work to improve the welfare of persons and communities by creating more convenient, equitable, healthful, efficient, and attractive places now and for the future. The centerpiece of urban planning activities is a "master plan," which can take many forms, including comprehensive plans, neighborhood plans, community action plans, regulatory and incentive strategies, economic development plans, and disaster preparedness plans. Traditionally, these plans include assessing and planning for community needs in some or all of the following areas: transportation, housing, commercial/office buildings, natural resource utilization, environmental protection, and health-care infrastructure. Urban planning and public health share common missions and perspectives. Both aim to improve human well-being, emphasize needs assessment and service delivery, manage complex social systems, focus at the population level, and rely on community-based participatory methods. Both fields focus on the needs of vulnerable populations. Throughout their development, both fields have broadened their perspectives. Initially, public health most often used a biomedical model (examining normal/abnormal functioning of the human organism), and urban planning often relied on a geographic model (analysis of human needs or interactions in a spatial context). However, both fields have expanded their tools and perspectives, in part because of the influence of the other. Urban planning and public health have been intertwined for most of their histories. In 1854, British physician John Snow used geographic mapping of an outbreak of cholera in London to identify a public water pump as the outbreak's source. Geographic analysis is a key planning tool shared by urban planning and public health. In the mid-1800s, planners such as Frederick Law Olmsted bridged the gap between the fields by advancing the concept that community design contributes to physical and mental health; serving as President Lincoln's U.S. Sanitary Commission Secretary; and designing hundreds of places, including New York's Central Park. By 1872, the disciplines were so aligned that two of the seven founders of the American Public Health Association were urban designers (an architect and a housing specialist). In 1926, the U.S. Supreme Court, in validating zoning and land-use law as a legal government authority in Village of Euclid v. Ambler Realty, cited the protection of public health as part of its justification. Other connections have included 1) pioneering urbanist Jane Jacobs, who during the 1960s, called for community design that offered safe and convenient options for walking, biking, and impromptu social interaction; and 2) the Healthy Cities movement, which began in Europe and the United States during the 1980s and now includes projects in approximately 1,000 cities that in various ways highlight the role of health as much more than the presence of medical care.

Mapping the health and environmental situation in informal zones in Aleppo, Syria: report from the Aleppo household survey.

OBJECTIVES: Despite large communities living in informal zones around major cities in Syria, there is currently no information on the health and environmental situations in these areas. From May to August 2004, the Syrian Center for Tobacco Studies (SCTS) conducted the first household survey aiming to provide a baseline map of main health problems and exposures affecting these communities in Aleppo, the second largest city in Syria (2,500,000 inhabitants). METHODS: Information on 1,021 participants randomly selected using stratified cluster sampling were available (46% males, mean age 34+/-11.7, age range 18-65 years, response rate 86%), including self-reported health/disability, exposures, and saliva cotinine measurement. RESULTS: Some positive findings include better than expected access to electricity, piped water, city sewage, and the use of propane for cooking. Particular areas of concern include high fertility rates, overcrowded housing conditions, and gender inequality in education and work. Household features likely to reflect negatively on residents' health include the use of diesel chimneys for heating and lack of smoking restrictions. Overall, residents of informal zones suffer from substantial physical and mental health problems and are exposed to high levels of indoor air pollution. All seem to affect women and the elderly disproportionately, while men are more affected by smoking, occupational respiratory exposures, and injuries. Both infectious and non-infectious respiratory outcomes were very common among study participants. Chronic and degenerative disease, including CVD and joint problems, were a source of substantial morbidity among the studied communities. CONCLUSIONS: This study highlights major health and environmental specificities of marginalized populations living in Aleppo, where women seem to bear a disproportionate burden of poor health and disability. Smoking and exposure to tobacco smoke seem among the major exposures facing these populations.

Cellular phones and risk of brain tumors.

As cellular telephones are a relatively new technology, we do not yet have long-term follow-up on their possible biological effects. However, the lack of ionizing radiation and the low energy level emitted from cell phones and absorbed by human tissues make it unlikely that these devices cause cancer. Moreover, several well-designed epidemiologic studies find no consistent association between cell phone use and brain cancer. It is impossible to prove that any product or exposure is absolutely safe, especially in the absence of very long-term follow-up. Accordingly, the following summary from the Food and Drug Administration Center for Devices and Radiological Health offers advice to people concerned about their risk: If there is a risk from these products--and at this point we do not know that there is--it is probably very small. But if people are concerned about avoiding even potential risks, there are simple steps they can take to do so. People who must conduct extended conversations in their cars every day could switch to a type of mobile phone that places more distance between their bodies and the source of the RF, since the exposure level drops off dramatically with distance. For example, they could switch to: a mobile phone in which the antenna is located outside the vehicle, a hand-held phone with a built-in antenna connected to a different antenna mounted on the outside of the car or built into a separate package, or a headset with a remote antenna to a mobile phone carried at the waist. Again the scientific data do not demonstrate that mobile phones are harmful. But if people are concerned about the radiofrequency energy from these products, taking the simple precautions outlined above can reduce any possible risk. In addition, people who are concerned might choose digital rather than analog telephones, since the former use lower RF levels.

Arsenic.

The toxicity and carcinogenicity of arsenic are well known, but vexing questions remain. The current controversy over the appropriate Federal limit for arsenic in drinking water highlights some of the difficult scientific, ethical, economic, and political issues that complicate standard-setting in occupational and environmental health. These include limitations in the scientific evidence concerning the risk at low doses, uncertainty about the appropriate mathematical models for estimating the risk at low-level exposures based on data from higher-level exposures, and controversies concerning the appropriate safety margin, level of evidence required for standard-setting, and costs of remediation.

Blood lead in children and its determinants in Nagpur, India.

In a community-based cross-sectional study of 297 children aged 6 months to 6 years in an Indian city, the authors assessed the prevalence of elevated (> or = 10 microg/dL) blood lead (PbB) levels, their risk factors, and the lead contents in potential environmental sources. Mean PbB was 18.4 microg/dL +/- 16.5. The prevalence of elevated PbB was 67%. Anticipated risk factors for elevated PbB were living in houses painted with lead-based paint, odds ratio (OR) 6.42 (1.75, 23.6; p = 0.005), recent exposures to lead-based paint, OR 2.61 (1.07, 6.66; p = 0.03), and the use of the eye cosmetic ma," OR 2.63 (1.24, 5.56; p = 0.01). Unanticipated results were effect of upper caste as a risk factor, OR (adjusted) 1.85 (95% CI = 0.96, 3.57; p = 0.06), and the lack of effect of traffic, parental occupational exposure, or nutritional status. Analysis of various environmental sources such as paint, pencils, crayons, and clay revealed high lead levels. These results demonstrate the existence of a major environmental health problem in Indian children, with risk factors that differ from those in other countries.

Diagnostic chelation challenge with DMSA: a biomarker of long-term mercury exposure?

Chelation challenge testing has been used to assess the body burden of various metals. The best-known example is EDTA challenge in lead-exposed individuals. This study assessed diagnostic chelation challenge with dimercaptosuccinic acid (DMSA) as a measure of mercury body burden among mercury-exposed workers. Former employees at a chloralkali plant, for whom detailed exposure histories were available (n = 119), and unexposed controls (n = 101) completed 24-hr urine collections before and after the administration of two doses of DMSA, 10 mg/kg. The urinary response to DMSA was measured as both the absolute change and the relative change in mercury excretion. The average 24-hr mercury excretion was 4.3 microg/24 hr before chelation, and 7.8 microg/24 hr after chelation. There was no association between past occupational mercury exposure and the urinary excretion of mercury either before or after DMSA administration. There was also no association between urinary mercury excretion and the number of dental amalgam surfaces, in contrast to recent published results. We believe the most likely reason that DMSA chelation challenge failed to reflect past mercury exposure was the elapsed time (several years) since the exposure had ended. These results provide normative values for urinary mercury excretion both before and after DMSA challenge, and suggest that DMSA chelation challenge is not useful as a biomarker of past mercury exposure.

Beyond toxicity: human health and the natural environment.

Research and teaching in environmental health have centered on the hazardous effects of various environmental exposures, such as toxic chemicals, radiation, and biological and physical agents. However, some kinds of environmental exposures may have positive health effects. According to E.O. Wilson's "biophilia" hypothesis, humans are innately attracted to other living organisms. Later authors have expanded this concept to suggest that humans have an innate bond with nature more generally. This implies that certain kinds of contact with the natural world may benefit health. Evidence supporting this hypothesis is presented from four aspects of the natural world: animals, plants, landscapes, and wilderness. Finally, the implications of this hypothesis for a broader agenda for environmental health, encompassing not only toxic outcomes but also salutary ones, are discussed. This agenda implies research on a range of potentially healthful environmental exposures, collaboration among professionals in a range of disciplines from public health to landscape architecture to city planning, and interventions based on research outcomes.

Reconstruction of occupational mercury exposures at a chloralkali plant.

OBJECTIVE: To reconstruct historical workplace exposure to mercury (Hg) from 1956 to 1994 at a large chloralkali factory for use in a current epidemiology study of the factory. METHODS: All job activities of the employees were classified into one of 16 exposure categories, and the dates of changes in the processes were identified. Exposures to Hg for each job category, at each period of the plant's operation, were then reconstructed from several data sources. A job-time period-exposure matrix was created, and the individual exposures of former workers were calculated. Data on exposure to Hg in air were compared with modelled concentrations of Hg in air and data on urinary Hg of the employees. RESULTS: Within an exposure category, concentrations of Hg in air were fairly constant for the first 20 years of the factory's operation, but began to increase in the late 1970s. Employees working in the cell room had the greatest exposures to Hg. The exposure estimates had significant correlations (p<0.001) with the urinary data and were well within the modelled range of concentrations of Hg in air. CONCLUSIONS: The highest exposures occurred from 1987 until the plant closed in early 1994 with some exposure categories having time weighted average exposures to Hg greater than 140 microg/m(3).

Health effects of long-term mercury exposure among chloralkali plant workers.

BACKGROUND: Inorganic mercury is toxic to the nervous system, kidneys, and reproductive system. We studied the health effects of mercury exposure among former employees of a chloralkali plant that operated from 1955 to 1994 in Georgia. METHODS: Former plant workers and unexposed workers from nearby employers were studied. Exposure was assessed with a job-exposure matrix based on historical measurements and personnel records. Health outcomes were assessed with interviews, physical examinations, neurological and neurobehavioral testing, renal function testing, and urinary porphyrin measurements. Exposure-disease associations were assessed with multivariate modeling. RESULTS: Exposed workers reported more symptoms, and tended toward more physical examination abnormalities, than unexposed workers. Exposed workers performed worse than unexposed subjects on some quantitative tests of vibration sense, motor speed and coordination, and tremor, and on one test of cognitive function. Few findings remained significant when exposure was modeled as a continuous variable. Neither renal function nor porphyrin excretion was associated with mercury exposure. CONCLUSIONS: Mercury-exposed chloralkali plant workers reported more symptoms than unexposed controls, but no strong associations were demonstrated with neurological or renal function or with porphyrin excretion.

Radon.

Residential and occupational exposure to radon is the second leading cause of lung cancer after cigarette smoking. As many as eight million homes in the US have elevated radon levels according to Environmental Protection Agency estimates. High exposure levels in homes are largely a result of radon-contaminated gas rising from the soil. This makes it an unusual indoor air pollutant in that it has a natural source. This study examines the synergism between smoking and radon, what levels are considered safe, and what to do to safeguard against overexposure to radon.

The international trade in toxic waste: the case of Sihanoukville, Cambodia.

In December 1998, 2,700 metric tons of industrial waste containing high levels of mercury and other metals and possibly other toxic compounds were shipped illegally from Taiwan to Sihanoukville, Cambodia. There the waste was unloaded and transferred to a nearby inland dumpsite. An estimated 2,000 Sihanoukville residents were exposed to the waste occupationally or environmentally, and at least six deaths and hundreds of injuries have been associated with the incident. The authors describe the human exposures and associated morbidity and mortality, recount the medical and public health response, and consider the issues complicating epidemiologic analysis of the incident. They also consider the major issues highlighted by the incident, including the trade in toxic waste between developed and less developed countries, the factors that shape emergency public health responses in resource-poor environments, and the importance of prevention and preparedness in containing emergencies in developing countries.

Occupational and environmental medicine and primary care.

This article introduces occupational and environmental medicine (OEM) to physicians in other specialties, and especially to primary care physicians, by highlighting the common foundations of OEM practice and primary care practice. These common foundations include careful diagnosis and treatment, appropriate use of consultants, collaboration with non-medical professionals, attention to psychosocial issues, care of the entire family, respect for confidentiality, patient education, preventing disability and maximizing function, diligent patient follow-up, epidemiological thinking, and continuing medical education.

Interim results of the study of particulates and health in Atlanta (SOPHIA).

Substantial evidence supports an association of particulate matter (PM) with cardiorespiratory illnesses, but little is known regarding characteristics of PM that might contribute to this association and the mechanisms of action. The Atlanta superstation sponsored by the Electric Power Research Institute as part of the Aerosol Research and Inhalation Epidemiology Study (ARIES) study is monitoring chemical composition of ambient particles by size fraction, as well as a comprehensive suite of other pollutants, at a site in downtown Atlanta during the 25-month period, August 1, 1998-August 31, 2000. Our investigative team is making use of this unique resource in several morbidity studies, called the "Study of Particulates and Health in Atlanta (SOPHIA)". The study includes the following components: (1) a time series investigation of emergency department (ED) visits for the period during which the superstation is operating; (2) a time series investigation of ED visits during the 5 years prior to implementation of the superstation; and (3) a study of arrhythmic events in patients equipped with automatic implantable cardioverter defibrillators (AICDs) for the period January 1, 1993-August 31, 2000. Thirty-three of 39 Atlanta area EDs are participating in the ED studies, comprising over a million annual ED visits. In this paper, we present initial analyses of data from 18 of the 33 participating EDs. The preliminary data set includes 1,662,713 ED visits during the pre-superstation time period and 559,480 visits during the superstation time period. Visits for four case groupings--asthma, chronic obstructive pulmonary disease (COPD), dysrhythmia, and all cardiovascular diseases (CVDs) combined--have been assessed relative to daily air quality indices, controlling for long-term temporal trends and meteorologic variables, using general linear models, generalized estimating equations and generalized additive models. Single-pollutant models predicting case visitation rates using moving averages of 0-, 1-, and 2-day lagged air quality variables were run. For the pre-superstation period, PM10 (24-h), ozone (8-h), SO2 (1-h), NO2 (1-h) and CO (1-h) were studied. For the first 12 months of superstation operation, the following air quality variables of a priori interest were available: ozone (8-h), NO2 (1-h), SO2 (1-h), CO (1-h), and 24-h measurements of PM10, coarse PM (PM 2.5-10 microm), PM2.5, polar VOCs, 10-100 nm particulate count and surface area, and in the PM2.5 fraction: sulfates, acidity, water-soluble metals, organic matter (OM), and elemental carbon (EC). During the pre-superstation time period, statistically significant, positive associations were observed for adult asthma with ozone, and for COPD with ozone, NO2 and PM10. During the superstation time period, the following statistically significant, positive associations were observed: dysrhythmia with CO, coarse PM, and PM2.5 EC; and all CVDs with CO, PM2.5 EC and PM2.5 OM. While covariation of many of the air quality indices limits the informativeness of this analysis, the study provides one of the first assessments of PM components in relation to ED visits.

Air quality and pediatric emergency room visits for asthma in Atlanta, Georgia, USA.

Pediatric emergency room visits for asthma were studied in relation to air quality indices in a spatio-temporal investigation of approximately 130,000 visits (approximately 6,000 for asthma) to the major emergency care centers in Atlanta, Georgia, during the summers of 1993-1995. Generalized estimating equations, logistic regression, and Bayesian models were fitted to the data. In logistic regression models comparing estimated exposures of asthma cases with those of the nonasthma patients, controlling for temporal and demographic covariates and using residential zip code to link patients to spatially resolved ozone levels, the estimated relative risk per 20 parts per billion (ppb) increase in the maximum 8-hour ozone level was 1.04 (p < 0.05). The estimated relative risk for particulate matter less than or equal to 10 microm in aerodynamic diameter (PM10) was 1.04 per 15 microg/m3 (p < 0.05). Exposure-response trends (p < 0.01) were observed for ozone (>100 ppb vs. <50 ppb: odds ratio = 1.23, p = 0.003) and PM10 (>60 microg/m3 vs. <20 microg/m3: odds ratio = 1.26, p = 0.004). In models with ozone and PM10, both terms became nonsignificant because of collinearity of the variables (r= 0.75). The other analytical approaches yielded consistent findings. This study supports accumulating evidence regarding the relation of air pollution to childhood asthma exacerbation.

Use of a job-exposure matrix to assess occupational exposures in relation to birth defects.

Accurate exposure assessment remains a challenge in occupational epidemiology. We evaluated one approach, use of a job-exposure matrix (JEM), by applying the National Institute for Occupational Safety and Health (NIOSH) JEM to a large case-control birth defects study that included parental occupation information. We investigated the JEM exposure predictions in several ways and found that for a substantial proportion of the parents in the birth defects study, the JEM yielded either no exposure data or nonsense predictions. Among exposure predictions that were plausible, most were of low probability. The high probability exposure predictions were statistically unstable, and neither low nor high probability exposure predictions were reliable. There was considerable discrepancy between the JEM predictions and expert assessments for five exposures of interest. Application of the NIOSH JEM to the birth defects study database (and probably other databases as well) does not provide a useful means of assessing occupational exposures.

Minority workers and communities.

Environmental and occupational hazards do not affect all communities equally. Members of ethnic and racial minorities, whether as working people or as community residents, sustain disproportionate risks from chemical, physical, and biological hazards. This paper reviews the nature of these disproportionate risks, focusing primarily on the workplace, but considering general environmental exposures as well. It discusses three principal mechanisms of increased risk: excessive hazardous exposures in both the workplace and the general environment, increased susceptibility, and inferior healthcare. It presents evidence that, as the result of these factors, members of minority groups display elevated rates of work-related illness, injury, fatality, and disability. Finally, it offers recommendations with regard to research, primary prevention, minority recruitment into the occupational health professions, and treatment and compensation for injured and ill minority workers.

Special populations in occupational health.

This introductory chapter lays the groundwork for the in-depth examination of special populations that follows. Drs. Frumkin and Pransky discuss what makes a population special, health disparities over the generations, and the evolving recognition of special populations in occupational health.