The association of PM(2.5) with full term low birth weight at different spatial scales.

There is interest in determining the relationship between fine particulate matter air pollution and various health outcomes, including birth outcomes such as term low birth weight. Previous studies have come to different conclusions. In this study we consider whether the effect may vary by location and gestational period. We also compare results when using different spatial resolutions for the air concentration estimates. Among the seven states considered, New Jersey and New York had the highest PM2.5 levels (average full gestation period exposures of 13 µg/m(3)) and the largest rate of low birth weight births (2.6 and 2.8%, respectively); conversely Utah and Minnesota had the lowest PM2.5 levels (9 µg/m(3)) and the lowest rates of low birth weight births (2.1 and1.9%, respectively). There is an association between PM2.5 exposure and low birth weight in New York for the full gestation period and all three trimesters, in Minnesota for the full gestation period and the first and third trimesters, and in New Jersey for the full gestation period and the first trimester. When we pooled the data across states, the OR for the full gestation period was 1.030 (95% CI: 1.022-1.037) and it was highest for the first trimester (OR 1.018; CI: 1.013-1.022) and decreasing during the later trimesters. When we used a finer spatial resolution, the strengths of the associations tended to diminish and were no longer statistically significant. We consider reasons why these differences may occur and their implications for evaluating the effects of PM2.5 on birth outcomes.

Effects of maternal exposure to phthalates and bisphenol A during pregnancy on gestational age.

OBJECTIVE: Phthalates and bisphenol A (BPA) are ubiquitous environmental toxicants, present in high concentrations in numerous consumer products. We hypothesized that maternal exposure to phthalates and BPA in pregnancy is associated with shortened gestation. METHODS: Urinary phthalate and BPA metabolites from 72 pregnant women were measured at the last obstetric clinic visit prior to delivery. Using linear regression models, we estimated the change in gestational age associated with each interquartile range (IQR) increase in phthalate and BPA metabolite concentration. RESULTS: IQR increases in urinary mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and BPA concentrations were associated with 4.2 and 1.1 d decreases in gestation, respectively. When stratified by gender, these alterations were found only in male infants. CONCLUSIONS: We conclude that MEHHP and BPA (free + glucuronide) are associated with reductions in gestation, with effects observed only in males. Our findings are consistent with the idea that these agents induce gender-specific alterations in signaling via PPAR-γ transcription factor, androgen precursors and/or inflammatory mediators during the initiation of labor.

Maternal exposure to particulate air pollution and term birth weight: a multi-country evaluation of effect and heterogeneity.

BACKGROUND: A growing body of evidence has associated maternal exposure to air pollution with adverse effects on fetal growth; however, the existing literature is inconsistent. OBJECTIVES: We aimed to quantify the association between maternal exposure to particulate air pollution and term birth weight and low birth weight (LBW) across 14 centers from 9 countries, and to explore the influence of site characteristics and exposure assessment methods on between-center heterogeneity in this association. METHODS: Using a common analytical protocol, International Collaboration on Air Pollution and Pregnancy Outcomes (ICAPPO) centers generated effect estimates for term LBW and continuous birth weight associated with PM(10) and PM(2.5) (particulate matter ≤ 10 and 2.5 µm). We used meta-analysis to combine the estimates of effect across centers (~ 3 million births) and used meta-regression to evaluate the influence of center characteristics and exposure assessment methods on between-center heterogeneity in reported effect estimates. RESULTS: In random-effects meta-analyses, term LBW was positively associated with a 10-µg/m3 increase in PM10 [odds ratio (OR) = 1.03; 95% CI: 1.01, 1.05] and PM(2.5) (OR = 1.10; 95% CI: 1.03, 1.18) exposure during the entire pregnancy, adjusted for maternal socioeconomic status. A 10-µg/m3 increase in PM(10) exposure was also negatively associated with term birth weight as a continuous outcome in the fully adjusted random-effects meta-analyses (-8.9 g; 95% CI: -13.2, -4.6 g). Meta-regressions revealed that centers with higher median PM(2.5) levels and PM(2.5):PM(10) ratios, and centers that used a temporal exposure assessment (compared with spatiotemporal), tended to report stronger associations. CONCLUSION: Maternal exposure to particulate pollution was associated with LBW at term across study populations. We detected three site characteristics and aspects of exposure assessment methodology that appeared to contribute to the variation in associations reported by centers.

The International Collaboration on Air Pollution and Pregnancy Outcomes: initial results.

BACKGROUND: The findings of prior studies of air pollution effects on adverse birth outcomes are difficult to synthesize because of differences in study design. OBJECTIVES: The International Collaboration on Air Pollution and Pregnancy Outcomes was formed to understand how differences in research methods contribute to variations in findings. We initiated a feasibility study to a) assess the ability of geographically diverse research groups to analyze their data sets using a common protocol and b) perform location-specific analyses of air pollution effects on birth weight using a standardized statistical approach. METHODS: Fourteen research groups from nine countries participated. We developed a protocol to estimate odds ratios (ORs) for the association between particulate matter ≤ 10 µm in aerodynamic diameter (PM10) and low birth weight (LBW) among term births, adjusted first for socioeconomic status (SES) and second for additional location-specific variables. RESULTS: Among locations with data for the PM10 analysis, ORs estimating the relative risk of term LBW associated with a 10-µg/m³ increase in average PM10 concentration during pregnancy, adjusted for SES, ranged from 0.63 [95% confidence interval (CI), 0.30-1.35] for the Netherlands to 1.15 (95% CI, 0.61-2.18) for Vancouver, with six research groups reporting statistically significant adverse associations. We found evidence of statistically significant heterogeneity in estimated effects among locations. CONCLUSIONS: Variability in PM10-LBW relationships among study locations remained despite use of a common statistical approach. A more detailed meta-analysis and use of more complex protocols for future analysis may uncover reasons for heterogeneity across locations. However, our findings confirm the potential for a diverse group of researchers to analyze their data in a standardized way to improve understanding of air pollution effects on birth outcomes.

Oral cleft defects and maternal exposure to ambient air pollutants in New Jersey.

BACKGROUND: Evidence links exposure to ambient air pollution during pregnancy, particularly gaseous pollutants and particulate matter, to an increased risk of adverse reproductive outcomes though the results for birth defects have been inconsistent. METHODS: We compared estimated exposure to ambient air pollutants during early pregnancy among mothers of children with oral cleft defects (cases) to that among mothers of controls, adjusting for available risk factors from birth certificates. We obtained ambient air pollutant data from air monitoring sites in New Jersey for carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO(2)), particulate matter <10 microm in aerodynamic diameter (PM10) and particulate matter <2.5 microm in aerodynamic diameter (PM2.5). We used values from the nearest monitor (within 40 km of the residence at birth) for controls, cleft lip with or without cleft palate (CLP) and cleft palate only (CPO). RESULTS: Based on logistic regression analyses for each contaminant and all contaminants together, there were no consistent elevated associations between selected air pollutants and cleft malformations. Quartile of CO concentration showed a consistent protective association with CPO (p < 0.01). For other contaminants, confidence intervals (95%) of the odds ratios for some quartiles excluded one. CLP showed limited evidence of an association with increasing SO(2) exposure while CPO showed weak associations with increasing O3 exposure. CONCLUSION: There was little consistent evidence associating cleft malformations with maternal exposure to ambient air pollutants. Evaluating particular pollutants or disease subgroups would require more detailed measurement of exposure and classification of cleft defects.

Privacy versus public health: the impact of current confidentiality rules.

Public health research and practice often have been facilitated through the evaluation and study of population-based data collected by local, state, and federal governments. However, recent concerns about identify theft, confidentiality, and patient privacy have led to increasingly restrictive policies on data access, often preventing researchers from using these valuable data. We believe that these restrictions, and the research impeded or precluded by their implementation and enforcement, have had a significant negative impact on important public health research. Members of the public health community should challenge these policies through their professional societies and by lobbying legislators and health officials to advocate for changes that establish a more appropriate balance between privacy concerns and the protection of public health.

Environmental justice: a contrary finding for the case of high-voltage electric power transmission lines.

Environmental justice is the consideration of whether minority and/or lower-income residents in a geographic area are likely to have disproportionately higher exposures to environmental toxins than those living elsewhere. Such situations have been identified for a variety of factors, such as air pollution, hazardous waste, water quality, noise, residential crowding, and housing quality. This study investigates the application of this concept to high-voltage electric power transmission lines (HVTL), which some perceive as a health risk because of the magnetic fields they generate, and also as esthetically unpleasing. We mapped all 345 kV and higher voltage HVTL in New York State and extracted and summarized proximate US Census sociodemographic and housing characteristic data into four categories on the basis of distances from HVTL. Contrary to our expectation, people living within 2000 ft from HVTL were more likely to be exposed to magnetic fields, white, of higher income, more educated and home owners, than those living farther away, particularly in urban areas. Possible explanations for these patterns include the desire for the open space created by the rights-of-way, the preference for new homes/subdivisions that are often located near HVTL, and moving closer to HVTL before EMFs were considered a risk. This study suggests that environmental justice may not apply to all environmental risk factors and that one must be cautious in generalizing. In addition, it shows the utility of geographical information system methodology for summarizing information from extremely large populations, often a challenge in epidemiology.

Birth and fetal death records and environmental exposures: promising data elements for environmental public health tracking of reproductive outcomes.

OBJECTIVES: We inventoried and reviewed the birth and fetal death certificates of all 50 U.S. states to identify nonstandard data items that are environmentally relevant, inexpensive to collect, and might enhance environmental public health tracking. METHODS: We obtained online or requested by mail or telephone the birth certificate and fetal death record forms or formats from each state. Every state data element was compared to the 2003 standards promulgated by the National Center for Health Statistics to identify any items that are not included on the standard. We then evaluated these items for their utility in environmentally related analyses. RESULTS: We found three data fields of potential interest. First, although every state included residence of mother at time of delivery on the birth certificate, only four states collected information on how long the mother had lived there. This item may be useful in that it could be used to assess and reduce misclassification of environmental exposures among women during pregnancy. Second, we found that father's address was listed on the birth certificates of eight states. This data field may be useful for defining paternal environmental exposures, especially in cases where the parents do not live together. Third, parental occupation was listed on the birth certificates of 15 states and may be useful for defining parental workplace exposures. Our findings were similar for fetal death records. CONCLUSION: If these data elements are accurate and well-reported, their addition to birth, fetal death, and other health records may aid in environmental public health tracking.

A computerized, self-administered questionnaire to evaluate posttraumatic stress among firefighters after the World Trade Center collapse.

OBJECTIVES: We sought to determine the frequency of psychological symptoms and elevated posttraumatic stress disorder (PTSD) risk among New York City firefighters after the World Trade Center (WTC) attack and whether these measures were associated with Counseling Services Unit (CSU) use or mental health-related medical leave over the first 2.5 years after the attack. METHODS: Shortly after the WTC attack, a computerized, binary-response screening questionnaire was administered. Exposure assessment included WTC arrival time and "loss of a co-worker while working at the collapse." We determined elevated PTSD risk using thresholds derived from Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, and a sensitivity-specificity analysis. RESULTS: Of 8487 participants, 76% reported at least 1 symptom, 1016 (12%) met criteria for elevated PTSD risk, and 2389 (28%) self-referred to the CSU, a 5-fold increase from before the attack. Higher scores were associated with CSU use, functional job impairment, and mental health-related medical leave. Exposure-response gradients were significant for all outcomes. CONCLUSIONS: This screening tool effectively identified elevated PTSD risk, higher CSU use, and functional impairment among firefighters and therefore may be useful in allocating scarce postdisaster mental health resources.

The future of epidemiology.

In this article, the authors discuss current challenges and opportunities in epidemiology that will affect the field's future. Epidemiology is commonly considered the methodologic backbone for the fields of public health and outcomes research because its practitioners describe patterns of disease occurrence, identify risk factors and etiologic determinants, and demonstrate the usefulness of interventions. Like most aspects of science, epidemiology is in rapid flux. Several factors that are influencing and will continue to influence epidemiology and the health of the public include factors fundamental to framing the discipline of epidemiology (i.e., its means of communication, its methodologies, its access to data, its values, its population perspective), factors relating to scientific advances (e.g., genomics, comparative effectiveness in therapeutics), and factors shaping human health (e.g., increasing globalism, the environment, disease and lifestyle, demographics, infectious disease).

Lack of association between estimated World Trade Center plume intensity and respiratory symptoms among New York City residents outside of Lower Manhattan.

Researchers have reported adverse health effects among rescue/recovery workers and people living near the World Trade Center on September 11, 2001. The authors investigated the occurrence of respiratory symptoms among persons living outside of Lower Manhattan in areas affected by the World Trade Center particulate matter plume. Using a novel atmospheric dispersion model, they estimated relative cumulative plume intensity in areas surrounding the World Trade Center site over a 5-day period following the collapse of the buildings. Using data from a telephone survey of residents (n = 2,755) conducted approximately 6 months after the event, the authors evaluated associations between the estimated plume intensities at individual residence locations and self-reported respiratory symptoms among nonasthmatics, as well as symptoms and nonroutine care among asthmatics. Comparing persons at or above the 75th percentile of cumulative plume intensity with those below it, there was no statistically significant difference in self-reported new-onset wheezing/cough after September 11 (16.1% vs. 13.3%; adjusted odds ratio = 1.0, 95% confidence interval: 0.7, 1.7) and no worsening of asthma from before September 11 to the 4 weeks prior to the survey (13.9% vs. 16.6%; odds ratio = 1.0, 95% confidence interval: 0.3, 2.8). These results suggest that the plume was not strongly associated with respiratory symptoms outside of Lower Manhattan, within the limitations of this retrospective study.

Environmental factors in cancer: trichloroethylene and related solvents: science, regulation, and cancer prevention.

In summary, I have used the case of TCE exposure as an example of: (1) The importance of population-based research to identify and characterize possible environmental risk factors for cancer, and the need for a greater emphasis and proportional increase in public funding of research on prevention as compared to treatment. We need to understand these risks better, and use this information to drive effective public health prevention actions. (2) The imposition of strong restrictions on requests by bona fide researchers for access to data as a barrier to research that could be used to help resolve some of the most controversial issues in TCE epidemiology, in particular, and environmental risks in general, especially access to individual level data including data of event and location of residence. Researchers need ready access these data to more accurately characterize environmental exposures, diseases and their possible associations, and to help develop more effective public health preventive actions, although they should also protect confidentiality. (3) The need for more accurate and comprehensive biomarkers of exposure and disease to better assess possible associations between environmental and occupational exposures and disease; (4) The role of non-scientific concerns in limiting regulatory and advisory agencies in the reevaluation of their positions relative to preventing or lowering allowable exposures to TCE, in light of the growing body of evidence on the possible carcinogenicity of a compound still widely in use, to which many workers, and substantial segments of the general public, are exposed.

Some considerations for the communication of results of air pollution health effects tracking.

Communicating effectively and efficiently on air quality and its health impacts is an important but difficult and complex task. It requires careful consideration of the audience one wants to reach, the messages one is trying to present, the venue through which the message will be delivered. The audience, context, technique, and content factors may affect how well it is heard and how appropriately it is interpreted. In this short paper, I describe many of these concerns and provide some suggestions for how best to address them. However, since every audience differs in goals, characteristics, and nature, what is most important is implementing an effective communications program. This program should include frequent two-way communication, repeated and on-going evaluation of how well the audience understands the messages, and consideration of how to improve the delivery.

Mortality of aircraft maintenance workers exposed to trichloroethylene and other hydrocarbons and chemicals: extended follow-up.

OBJECTIVE: To extend follow-up of 14,455 workers from 1990 to 2000, and evaluate mortality risk from exposure to trichloroethylene (TCE) and other chemicals. METHODS: Multivariable Cox models were used to estimate relative risk (RR) for exposed versus unexposed workers based on previously developed exposure surrogates. RESULTS: Among TCE-exposed workers, there was no statistically significant increased risk of all-cause mortality (RR = 1.04) or death from all cancers (RR = 1.03). Exposure-response gradients for TCE were relatively flat and did not materially change since 1990. Statistically significant excesses were found for several chemical exposure subgroups and causes and were generally consistent with the previous follow-up. CONCLUSIONS: Patterns of mortality have not changed substantially since 1990. Although positive associations with several cancers were observed, and are consistent with the published literature, interpretation is limited due to the small numbers of events for specific exposures.

Developing integrated multistate environmental public health surveillance.

Environmental exposures cause substantial morbidity and mortality in the United States. A major goal of Centers for Disease Control and Prevention Environmental Public Health Tracking program is the development of a national network of health and environmental data with analytic tools for rapid evaluation of specific national or regional environmental health concerns. A six-state collaborative project in the northeast United States was established to assess the feasibility of such a system, assessing the possible association between ambient air quality and adverse birth outcomes. For this regional surveillance project, issues were discussed surrounding the design of a mutually acceptable protocol, obtaining human subjects' protection approvals, obtaining and organizing both the exposure and outcome data, analyzing the data both locally and regionally, and planning subsequent interventions to address identified public health concerns.

Poverty, environment, and health: the role of environmental epidemiology and environmental epidemiologists.

International attention is focusing increasingly on environmental concerns, from global warming and extreme weather to persistent chemical pollutants that affect our food supplies, health and well-being. These environmental exposures disproportionately affect the poor and those residing in developing countries, and may partly explain the persistent social gradients in health that exist within and between nations. We support recent calls for environmental epidemiologists to play a more active role in furthering the global agenda for sustainability, environmental health and equity. We further suggest that the discipline of environmental epidemiology, as well as relevant funding agencies, broaden their focus to include rigorous research on the upstream, larger-scale societal factors that contribute to inequitable patterns of exposure and health outcomes. By widening the scope of our vision and increasing the strength and breadth of the evidence base about how poverty and environment together affect health, we can better participate in efforts to promote social justice and responsible use and protection of the environment, and thus reduce health inequities. That is both a primary mode and rationale for achieving sustainability.

Surveillance of workers responding under the National Response Plan.

The National Response Plan (NRP) establishes the framework for the nation's response to major disasters. We offer seven recommendations related to surveillance of workers who respond to events under the NRP. These recommendations address the rationale for and principles of medical surveillance in the context of large-scale disasters and the NRP; means of identifying and registering the populations that should be included in surveillance activities; the role of exposure assessment in medical surveillance; behavioral health issues; and principles regarding the communication and use of surveillance data.

Cancer screening in women: body mass index and adherence to physician recommendations.

BACKGROUND: The reasons that obese women are less likely to obtain mammograms and Papanicolaou tests (Pap smears) are poorly understood. This study evaluated associations between body mass index (BMI) and receipt of and adherence to physician recommendations for mammography and Pap smear. METHODS: Data from the 2000 National Health Interview Survey (8289 women aged 40 to 74 years) were analyzed in 2006 using logistic regression. Women with previous hysterectomy were excluded from Pap smear analyses (n=5521). Outcome measures were being up-to-date with screening, receipt of physician recommendations, and women's adherence to physician recommendations for mammography and Pap smear. RESULTS: After adjusting for sociodemographic variables, healthcare access, health behaviors, and comorbidity, severely obese women (BMI > 40 kg/m(2)) were less likely to have had mammography within 2 years (odds ratio [OR]=0.50, 95% confidence interval [CI]=0.37-0.68) and a Pap smear within 3 years (OR=0.43, 95% CI=0.27-0.70). Obese women were as likely as normal-weight women to receive physician recommendations for mammography and Pap smear. Severely obese women were less likely to adhere to physician recommendations for mammography (OR=0.49, 95% CI=0.32-0.76). Women in all obese categories (BMI > 30 kg/m(2)) were less likely to adhere to physician recommendations for Pap smear (ORs ranged from 0.17 to 0.28, p<0.001). CONCLUSIONS: Obese women are less likely to adhere to physician recommendations for breast and cervical cancer screening. Interventions focusing solely on increasing physician recommendations for mammography and Pap smears will probably be insufficient for obese women. Additional strategies are needed to make cancer screening more acceptable for this high-risk group.

Current practices in spatial analysis of cancer data: mapping health statistics to inform policymakers and the public.

BACKGROUND: To communicate population-based cancer statistics, cancer researchers have a long tradition of presenting data in a spatial representation, or map. Historically, health data were presented in printed atlases in which the map producer selected the content and format. The availability of geographic information systems (GIS) with comprehensive mapping and spatial analysis capability for desktop and Internet mapping has greatly expanded the number of producers and consumers of health maps, including policymakers and the public.Because health maps, particularly ones that show elevated cancer rates, historically have raised public concerns, it is essential that these maps be designed to be accurate, clear, and interpretable for the broad range of users who may view them. This article focuses on designing maps to communicate effectively. It is based on years of research into the use of health maps for communicating among public health researchers. RESULTS: The basics for designing maps that communicate effectively are similar to the basics for any mode of communication. Tasks include deciding on the purpose, knowing the audience and its characteristics, choosing a media suitable for both the purpose and the audience, and finally testing the map design to ensure that it suits the purpose with the intended audience, and communicates accurately and effectively. Special considerations for health maps include ensuring confidentiality and reflecting the uncertainty of small area statistics. Statistical maps need to be based on sound practices and principles developed by the statistical and cartographic communities. CONCLUSION: The biggest challenge is to ensure that maps of health statistics inform without misinforming. Advances in the sciences of cartography, statistics, and visualization of spatial data are constantly expanding the toolkit available to mapmakers to meet this challenge. Asking potential users to answer questions or to talk about what they see is still the best way to evaluate the effectiveness of a specific map design.