Ambient Air Pollution and Hypertensive Disorders of Pregnancy: A Systematic Review and Meta-analysis.

Hypertensive disorders of pregnancy (HDP, including gestational hypertension, preeclampsia, and eclampsia) have a substantial public health impact. Maternal exposure to high levels of air pollution may trigger HDP, but this association remains unclear. The objective of our report is to assess and quantify the association between maternal exposures to criteria air pollutants (ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter ≤ 10, 2.5 µm) on HDP risk. PubMed, EMBASE, MEDLINE, Current Contents, Global Health, and Cochrane were searched (last search: September, 2013). After a detailed screening of 270 studies, 10 studies were extracted. We conducted meta-analyses if a pollutant in a specific exposure window was reported by at least four studies. Using fixed- and random-effects models, odds ratios (ORs) and 95% CIs were calculated for each pollutant with specific increment of concentration. Increases in risks of HDP (OR per 10 ppb = 1.16; 95% CI, 1.03-1.30) and preeclampsia (OR per 10 ppb = 1.10; 95% CI, 1.03-1.17) were observed to be associated with exposure to NO2 during the entire pregnancy, and significant associations between HDP and exposure to CO (OR per 1 ppm = 1.79; 95% CI, 1.31-2.45) and O3 (OR per 10 ppb = 1.09; 95% CI, 1.05-1.13) during the first trimester were also observed. Our review suggests an association between ambient air pollution and HDP risk. Although the ORs were relatively low, the population-attributable fractions were not negligible given the ubiquitous nature of air pollution.

Fish consumption patterns and mercury exposure levels among women of childbearing age in Duval County, Florida.

Consumption of fish containing methylmercury can pose serious health concerns including neurotoxic effects in adults and toxicity to the fetuses of mothers exposed during pregnancy. In the study described in this article, the authors examined fish consumption patterns and measured hair mercury levels of women of childbearing age in a coastal county in Florida. Women from the community participated in a risk factor assessment survey (N = 703). Hair samples (n = 698) were collected and analyzed for mercury. The authors identified 74.8% below detection limit; 25.2% had detectable limits of mercury, while 7% exceeded 1 pg/g. Hair mercury levels increased with fish consumption and age. Race, income, and education levels were also associated with increased hair mercury levels. Women of Asian/Pacific Islander origin had the highest levels. Although reported fish consumption exceeded the recommendations for women of childbearing age, the study population had lower mercury levels than other comparative studies in Florida and at national levels.

Urinary trichlorophenol levels and increased risk of attention deficit hyperactivity disorder among US school-aged children.

BACKGROUND: Trichlorophenols (TCPs) are organochlorine compounds which are ubiquitous in the environment and well known for their carcinogenic effects. However, little is known about their neurotoxicity in humans. OBJECTIVES: Our goal was to examine the association between body burden of TCPs (ie, 2,4,5-TCP and 2,4,6-TCP) and attention deficit hyperactivity disorder (ADHD). METHODS: We calculated ORs and 95% CIs from logistic regression analyses using data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES) to evaluate the association between urinary TCPs and parent-reported ADHD among 2546 children aged 6-15 years. RESULTS: Children with low levels (<3.58 µg/g) and high levels (≥3.58 µg/g) of urinary 2,4,6-TCP had a higher risk of parent-reported ADHD compared to children with levels below the limit of detection (OR 1.54, 95% CI 0.97 to 2.43 and OR 1.77, 95% CI 1.18 to 2.66, respectively; p for trend=0.006) after adjusting for covariates. No association was found between urinary 2,4,5-TCP and parent-reported ADHD. CONCLUSION: Exposure to TCP may increase the risk of behavioural impairment in children. The potential neurotoxicity of these chemicals should be considered in public health efforts to reduce environmental exposures/contamination, especially in countries where organochlorine pesticides are still commonly used.

Bladder cancer clusters in Florida: identifying populations at risk.

PURPOSE: Modifiable risk factors for bladder cancer have been identified, ie tobacco and chemical exposure. We identified high risk bladder cancer areas and risk factors associated with bladder cancer clusters in Florida using individual and area based data. MATERIALS AND METHODS: Spatial modeling was applied to 23,266 early and advanced bladder cancer cases diagnosed between 1998 and 2002 in Florida to identify areas of excess bladder cancer risk. Multivariable regression was used to determine whether sociodemographic indicators, smoking history and proximity to known arsenic contaminated drinking water well sites were associated with bladder cancer diagnosis in a specific area (cluster). RESULTS: A total of 25 clusters were found to have a higher than expected bladder cancer rate, including 13 and 12 of early and late stage disease, respectively. Urban white patients were more likely to live in an advanced bladder cancer cluster. Advanced bladder cancer cluster membership was associated with living in close proximity to known arsenic contaminated drinking water wells. CONCLUSIONS: There are multiple areas of early and late stage bladder cancer clusters in Florida. Individuals in an advanced bladder cancer cluster tended to live close to arsenic contaminated wells. Increased evaluation of potentially contaminated well water is warranted in these high risk areas. Targeted bladder cancer public awareness campaigns, smoking cessation support and potentially targeted screening should also be considered in communities at increased risk for bladder cancer. Our analytical approach can also be used by others to systematically identify communities at high risk for bladder and other cancers.

A spatial evaluation of socio demographics surrounding National Priorities List sites in Florida using a distance-based approach.

BACKGROUND: Over the last two decades, various spatial techniques have been demonstrated using geographical information systems (GIS) to adequately estimate and characterize inequities of minority populations living near environmentally hazardous facilities. However, these methods have produced mixed results. In this study, we use recently developed variations of the "distance based" approach to spatially evaluate and compare demographic and socioeconomic disparities surrounding the worst hazardous waste sites in Florida. METHODS: We used data from the 2000 US Census Bureau and the Florida Department of Environmental Protection to identify selected socio and economic variables within one (1) mile of 71 National Priorities List (NPL) or Superfund sites in Florida. ArcMap (ESRI, v. 9.2) was used to map the centroid locations of each of the NPL sites as well as identify and estimate the number of host and non-host tracts. The unit of analysis in this study was at the census tract level. Logistic regression (SAS v9.1.3) was used to determine if race/ethnicity and socioeconomic indicators are significant predictors of the location of NPL sites. RESULTS: There were significant differences in race/ethnicity composition and socio-economic factors between NPL host census tracts and non-host census tracts in Florida. The percentages of Blacks (OR = 5.7, p < 0.001), the percentage of Hispanic/Latino (OR = 5.84, p < 0.001), and percent employed in blue collar occupations (OR = 2.7, p < 0.01) were significant predictors of location of NPL facilities. CONCLUSION: The recently developed distance-based method supports previous studies and suggests that race and ethnicity play substantial roles in where hazardous facilities are located in Florida. Recommendations include using distance-based methods to evaluate socio and demographic characteristics surrounding other less known environmental hazardous facilities, such as landfills, or Toxic Release Inventory (TRI) sites.

Association between exposure to alkylbenzenes and cardiovascular disease among National Health and Nutrition Examination Survey (NHANES) participants.

Numerous studies have demonstrated that air pollution is associated with an increased risk of mortality and morbidity due to cardiovascular disease (CVD). Alkylbenzenes are ubiquitous in outdoor and indoor air environments. Yet few studies have evaluated the potential links between exposures to alkylbenzenes and CVD independent of tobacco smoking. In this study, we used the 1999-2004 National Health and Nutrition Examination Survey (NHANES) to examine the relationship between alkylbenzenes (toluene, styrene, ethylbenzene, and the xylenes) and CVD prevalence. All five alkylbenzenes suggested linear trends. Subjects in higher exposure categories of blood alkylbenzenes had higher prevalence of CVD, as compared to subjects in the reference group, of below the limit of detection (LOD) and less than the 50th percentile in the case of toluene and styrene. For the remainder of the alkylbenzes, similar statistically significant associations were observed. Further studies are needed to explore associations between these highly prevalent pollutants and CVD.

Tracking childhood exposure to lead and developmental disabilities: examining the relationship in a population-based sample.

Elevated levels of lead detected in the blood are associated with harmful effects on children's learning and behavior. The goal of the current Environmental Public Health Tracking Project was to examine the relationship between selected developmental disabilities and childhood blood lead levels in a population-based sample. Using extant datasets from the Florida Department of Health, Childhood Lead Poisoning Prevention Program, and the Florida Department of Education, we were able to isolate a linked dataset of children who were tested for lead poisoning and attended public schools. Special education categories served as a proxy for developmental disabilities; the prevalence of these disabilities in the sample of children with blood lead levels was compared with that in children who attended the same schools but were not tested for lead poisoning. Results indicated that children screened for lead poisoning were more likely to be receiving services for behavior problems, mental retardation, learning disabilities, or a speech-language impairment than other children attending the same schools. Implications for using administrative datasets to examine this relationship are discussed.

A procedure for detecting childhood cancer clusters near hazardous waste sites in Florida.

Despite over 20 years of research on childhood cancer clusters and hazardous waste sites, little evidence has been produced to indicate a causal relationship. Nevertheless, the perception of a childhood cancer cluster being located near a hazardous waste site can raise fear and uncertainty, and it demands attention from health officials. To investigate this public health concern, the author used the spatial-scan statistical software SaTScan to detect childhood cancer clusters and their proximity to National Priority List (NPL), or Superfund, sites in Florida. In the ecological study reported here, "most likely" clusters were defined as those with a p-value of < .05. Distance served as a proxy for exposure; a geographical information system (GIS) was used to determine the number of clusters within a predetermined distance of an NPL site. Spatial clusters were found to occur randomly throughout the state, with most clusters being identified in the more populated counties, and clusters less likely to occur near an NPL site. This article attempts to explain the utility of an emerging public health surveillance tool for detecting cancer clusters near hazardous waste sites. Despite several epidemiological limitations of the study, as well as the fact that there are other environmental exposure hazards such as Toxic Release Inventory facilities and landfills, the SaTScan program proved useful as a surveillance tool for generating more in-depth studies.

Predictors for Using a HIV Self-Test Among Migrant and Seasonal Farmworkers in North Carolina.

BACKGROUND: Approximately, two million migrant and seasonal farmworkers (MSF) work in the United States annually. Several factors, such as lack of access to healthcare services and health behaviors, contribute to risk of HIV transmission. Relatively few studies have explored MSF knowledge of HIV transmission and testing options. METHODS: A 12-question, self-administered survey of farmworkers (n = 178) from 19 migrant camps was conducted. The survey assessed knowledge of factors related to HIV transmission, testing, and intention to use a HIV home-test kit. RESULTS: Participants with knowledge of treatment for HIV (p = 0.03) and that condom use protects against HIV (p = 0.04) were more willing to express intent to use a home test kit than those with less knowledge. Concern among farmworkers that HIV was a very or somewhat serious problem in their community was associated with expressing intent to use a home test kit (OR = 2.3, 95% CI = 0.92-5.5). Respondents with less knowledge were less likely to use a home test kit. CONCLUSIONS: MSF were concerned about HIV in their community and would be willing to use to a home test kit. This pilot study provides a basis for additional research related to HIV testing within the MSF community.

Population attributable risks of neurobehavioral disorders due to low birth weight in US children.

BACKGROUND: The prevalence of low birth weight (LBW) and neurobehavioral disorders (N) has increased over the last three decades. However, it is unclear how many excess cases of ND can be attributed to LBW among U.S. children. The objectives of this study were to a) determine the association between LBW and ND including attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), behavior and conduct disorder (BCD) and learning disability (LD); and b) determine the population attributable risk (PAR) of these disorders due to LBW. METHODS: Study subjects were a nationally representative cross-sectional sample of 85,637 children ages 2 to 17 years old who participated in the 2011 National Survey of Children's Health. Birth weight and ND were reported by parents. RESULTS: LBW accounted for 6.0% (95% confidence interval [CI] 2.3-10.4) of all ASD cases, 2.4% (CI 0.1-5.1) of BCD, and 6.8% (CI 4.8-9.0) of LD among the study population. There was not a significant association between LBW and ADHD. The percentages of these ND due to LBW were found to be higher among those who were pre-term and among ethnic minority groups. CONCLUSIONS: Based on our results and given that over 8% of U.S. children are born with LBW, with higher rates among minorities and preterm births, prospective planning for neurobehavioral services is warranted. Efforts to reduce ND in children align with national efforts to reduce LBW.

Potential health impacts of heavy metals on HIV-infected population in USA.

PURPOSE: Noninfectious comorbidities such as cardiovascular diseases have become increasingly prevalent and occur earlier in life in persons with HIV infection. Despite the emerging body of literature linking environmental exposures to chronic disease outcomes in the general population, the impacts of environmental exposures have received little attention in HIV-infected population. The aim of this study is to investigate whether individuals living with HIV have elevated prevalence of heavy metals compared to non-HIV infected individuals in United States. METHODS: We used the National Health and Nutrition Examination Survey (NHANES) 2003-2010 to compare exposures to heavy metals including cadmium, lead, and total mercury in HIV infected and non-HIV infected subjects. RESULTS: In this cross-sectional study, we found that HIV-infected individuals had higher concentrations of all heavy metals than the non-HIV infected group. In a multivariate linear regression model, HIV status was significantly associated with increased blood cadmium (p=0.03) after adjusting for age, sex, race, education, poverty income ratio, and smoking. However, HIV status was not statistically associated with lead or mercury levels after adjusting for the same covariates. CONCLUSIONS: Our findings suggest that HIV-infected patients might be significantly more exposed to cadmium compared to non-HIV infected individuals which could contribute to higher prevalence of chronic diseases among HIV-infected subjects. Further research is warranted to identify sources of exposure and to understand more about specific health outcomes.

Studying associations between urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) and cardiovascular diseases in the United States.

The association between background, enduring environmental exposure to polycyclic aromatic hydrocarbons (PAHs) and cardiovascular diseases has not been well studied in the general population. In this study, we used the National Health and Nutrition Examination Survey (NHANES) 2001-2004 to investigate the associations between eight monohydroxy PAHs (OH-PAHs) and self-report CVD. In a logistic regression model adjusting for cigarette smoking and other covariates, phenanthrene metabolite, 2-hydroxyphennathrene (2-PHEN), was significantly associated with self-report CVD. Compared to subjects within the lowest tertile of 2-PHEN, subjects within the middle and highest tertiles had higher self-report CVD (the 2nd tertile: AOR=1.29, 95%CI: 0.97-1.72; the 3rd tertile: AOR=1.45, 95%CI: 1.01-2.07; p for trend=0.04). In addition, fluorene metabolite (i.e. 2-hydroxyfluorene) also showed a marginally significant linear trend with self-report CVD (p for trend=0.07). Further studies are necessary to explore the associations between these highly prevalent pollutants and CVD.

Associations of serum concentrations of organochlorine pesticides with breast cancer and prostate cancer in U.S. adults.

BACKGROUND: Organochlorine (OC) pesticides are a group of environmental endocrine disruptors that may be associated with an increased risk for hormone-related cancers including cancers of the breast and prostate. However, epidemiologic evidence is limited and inconsistent. OBJECTIVES AND METHODS: We used 1999-2004 National Health and Nutrition Examination Survey data to examine associations between serum concentrations of OC pesticides and prostate and breast cancers. RESULTS: After adjustment for other covariates, serum concentrations of beta-hexachlorocyclohexane (HCH) (p for trend = 0.02), trans-nonachlor (p for trend = 0.002), and dieldrin (p for trend = 0.04) were significantly associated with the risk of prevalent prostate cancer. Adjusted odds ratios for the second and third tertiles of detectable values were 1.46 [95% confidence interval (CI), 0.52-4.13] and 3.36 (95% CI, 1.24-9.10) for beta-HCH; 5.84 (95% CI, 1.06-32.2) and 14.1 (95% CI, 2.55-77.9) for trans-nonachlor; and 1.06 (95% CI, 0.30-3.73) and 2.74 (95% CI, 1.01-7.49) for dieldrin compared with concentrations in the lowest tertile or below the limit of detection. However, there was no positive association between serum concentrations of OC pesticides and breast cancer prevalence. CONCLUSION: Although further study is necessary to confirm these findings, these results suggest that OC pesticide exposures may have a significant effect on cancer risk. Efforts to reduce worldwide OC use are warranted.

Linking health and environmental data in geographical analysis: it's so much more than centroids.

Programs and studies increasingly use existing data from multiple sources (e.g., surveillance systems, health registries, or governmental agencies) for analysis and inference. These data usually have been collected on different geographical or spatial units, with each varying from the ones of interest. Combining such disparate data creates statistical challenges. Florida's efforts to move toward implementing the Centers for Disease Control and Prevention (CDC)'s Environmental Public Health Tracking (EPHT) program aptly illustrate these concerns, which are typical of studies designed to measure the association between environmental and health outcomes. In this paper, we develop models of spatial associations between myocardial infarctions (MIs) and ambient ozone levels in Florida during August 2005 and use these models to illustrate the problems that can occur when making inferences from aggregated data, the concept of spatial support, and the importance of correct uncertainty assessment. Existing data on hospital discharges and emergency department visits were obtained from Florida's Agency for Health Care Administration. Environmental data were obtained from Florida's Department of Environmental Protection; sociodemographic data were obtained from the US Census Bureau; and data from CDC's Behavioral Risk Factor Surveillance System were used to provide additional information on other risk factors. We highlight the opportunities and challenges associated with combining disparate spatial data for EPHT analyses. We compare the results from two different approaches to data linkage, focusing on the need to account for spatial scale and the support of spatial data in the analysis. We use geographically weighted regression, not as a visual mapping tool, but as an inferential tool designed to indicate the need for spatial coefficients, a test that cannot be made by using the majority of Bayesian models. Finally, we use geostatistical simulation methods for uncertainty analysis to demonstrate its importance in models with predicted covariates. Our focus is on relatively simple methods and concepts that can be implemented with ESRI's(®) ArcGIS(®) software.

Assessing the association between environmental impacts and health outcomes: a case study from Florida.

The Centers for Disease Control and Prevention (CDC) created the Environmental Public Health Tracking (EPHT) program to integrate hazard monitoring, exposure, and health effects surveillance into a cohesive tracking network. Part of Florida's effort to move toward implementation of EPHT is to develop models of the spatial and temporal association between myocardial infarctions (MIs) and ambient ozone levels in Florida. Existing data were obtained from Florida's Agency for Health Care Administration, Florida's Department of Environmental Protection, the U.S. Census Bureau, and CDC's Behavioral Risk Factor Surveillance System. These data were linked by both ignoring spatial support and using block kriging, a support-adjusted approach. The MI data were indirectly standardized by age, race/ethnicity, and sex. The state of Florida was used as the comparison standard to compute the MI standardized event ratio (SER) for each county and each month. After the data were linked, global models were used initially to relate MIs to ambient ozone levels, adjusting for covariates. The global models provide an estimated relative MI SER for the state. Realizing that the association in MIs and ozone might change across locations, local models were used to estimate the relative MI SER for each county, again adjusting for covariates. Results differed, depending on whether the spatial support was ignored or accounted for in the models. The opportunities and challenges associated with EPHT analyses are discussed and future directions highlighted.