National Air Toxics Assessment Research Articles

Abstract D096: Disparities in toxic heavy metal burden and breast cancer risk: Findings from the Metropolitan Chicago Breast Cancer Registry

Abstract BACKGROUND: Evidence regarding associations of ambient toxic heavy metals (THMs) and breast cancer (BC) incidence is mixed. Observed inconsistencies may be a consequence of utilizing ambient THM levels collected close to time of BC diagnosis, and not incorporating an appropriate latent period. In addition, most studies have not examined associations of ambient THMs and BC incidence stratified by estrogen receptor (ER) and menopausal status, and have examined relatively homogenous populations of non-Hispanic White (nHW) women. We examined time-to-event associations of ambient THM concentrations and BC subtypes among women enrolled in the racially/ethnically diverse Metropolitan Chicago Breast Cancer Registry (MCBCR) cohort. METHODS: Using the Environmental Protection Agency’s 2005 National Air Toxics Assessment (NATA), we examined census tract-level ambient concentrations for 11 THMs (antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel, and selenium). For women enrolled in MCBCR between 2003-2007, residential addresses were geocoded and matched to census-tract estimates of the ambient THM concentrations. Women were followed to time of BC diagnosis or December 31, 2014. Cox proportional hazards (PH) regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI), adjusted for age and race. RESULTS: Over a mean follow up time of 10 years, there were 6,579 incident BC cases (with a mean time to diagnosis of 3 years) and 205,095 cancer-free women in the cohort. Over a quarter of our study population was African American (AA), and nearly 10% were Hispanic. Compared to nHW women, AA women were more likely to reside in census tracts with higher quartile ambient concentrations of beryllium, cadmium, chromium, cobalt, lead, manganese, and mercury (p<0.001 for all). Similarly, Hispanic women were more likely to reside in census tracts characterized by higher quartile oncentrations of beryllium, cadmium, chromium, lead, manganese, mercury, and nickel (p<0.001 for all). In age and race adjusted models, compared to women residing in census tracts with the lowest quartile of ambient concentrations, increased BC incidence was observed for women residing in census tracts with the highest quartile of ambient concentrations of antimony (HR=1.08, 95% CI 1.00-1.17), beryllium (HR=1.09, 95% CI 1.01-1.18), cadmium (HR=1.07, 95% CI 1.00-1.17), lead (HR=1.18, 95% CI 1.09, 1.28), and nickel (HR=1.24, 95% CI 1.15-1.33). In models stratified by ER status and menopausal status, associations with beryllium, lead, and nickel were stronger for ER positive post-menopausal BC. Associations with antimony and cadmium were stronger for ER-negative BC risk. DISCUSSION: We found that African American and Hispanic women were disproportionately exposed to higher levels of ambient THMs, which in turn were associated with specific subtypes of BC. Future studies will focus on determinants of these observed environmental disparities in the MCBCR cohort. Citation Format: Alpana Kaushiva, Jacob Kresovich, Serap Erdal, Garth Rauscher. Disparities in toxic heavy metal burden and breast cancer risk: Findings from the Metropolitan Chicago Breast Cancer Registry [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D096.

Abstract A007: Using latent class modeling to characterize exposome impacts on health disparities

Abstract Recent work suggests that air pollutants, toxic chemicals, and other environmental exposures negatively impact health in a synergistic way. We hypothesize that these environmental exposures will vary with socioeconomic status (SES), and urban versus rural location, and contribute to health disparities. In order to measure and understand this phenomenon, we propose a latent class mixture model of multi-pollutant exposures and SES. This builds on our previous development of an SES mixture model, which includes 13 indicators of socioeconomic advantage (eg profession, education) and disadvantage (eg unemployment, single-parent households, etc). Our model identifies levels of joint exposure to three classes of toxic pollutants: volatile organic compounds (VOC), particulate matter (PM) and heavy metals (HM). We use publicly available data from the American Community Survey and the EPA, including the National Air Toxics Assessment (NATA), for the 2,174 census tracts in North Carolina (NC). Model results indicate that mixtures of 2 levels of pollutants, 2 levels of socioeconomic advantage and 2 levels of socioeconomic disadvantage best fit data for NC. We present estimated class-membership for the state of NC, where 34.1% of the census tracts exhibit high disadvantage, 66.3% have low advantage, and 59.2% of census tracts have high mixtures of toxic pollutants. While frequently observed in urban or regional city/suburban areas, our model shows that rural areas are detected at the highest levels of pollution as well. Areas of high advantage are focused on urban/suburban and coastal areas, while disadvantage dominates the eastern half of the state as well as many urban areas. Areas with higher SES disadvantage had significantly higher black population density (p<0.001). Similarly, black population density was higher in areas with higher pollution (p<0.001). Our next focus is to incorporate spatial correlations into our models to better characterize the interactive nature of multi-pollutant and economic exposures, and apply to specific cohorts with cancer outcomes. Taken together, these extensions will be incorporated into a holistic, exposome modelling framework for estimating disparities in cancer survival. Citation Format: Alexandra Larsen, Viktoria Kolpacoff, Victoria Seewaldt, Terry Hyslop. Using latent class modeling to characterize exposome impacts on health disparities [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A007.

Ancestry-Based Intracategorical Injustices in Carcinogenic Air Pollution Exposures in the United States

Previous studies of US environmental inequalities have focused on racial/ethnic differences in air pollutant exposure. Few have applied an intracategorical framework, which enables the identification of within-group differences through the examination of subgroups. We applied this framework to examine exposure disparities between 26 ancestry/ethnic origin groups within five US racial/ethnic categories. Data came from the US Census, American Community Survey, and National Air Toxics Assessment. We calculated national population-weighted lifetime cancer risk (LCR) scores from residential exposure to hazardous air pollutants. Results showed that Americans of Dominican, Ethiopian, and Somalian descent have the highest total LCR scores at 53.1, 49.2, and 48.3 estimated excess cases of cancer per one million people, respectively. Use of the intracategorical framework enabled characterization of disparate risks that would be overlooked based on the conventional assumption that racial/ethnic environmental inequalities conform to broad, homogenous categories. Intracategorical studies can inform interventions by identifying environmentally-disadvantaged socio-demographic groups.

Clustering of cutaneous T-cell lymphoma is associated with increased levels of the environmental toxins benzene and trichloroethylene in the state of Georgia.

Cutaneous T-cell lymphoma (CTCL) is a rare form of non-Hodgkin lymphoma arising in the skin. Geographic clustering of CTCL has recently been reported, but its association with environmental factors is unknown. Benzene and trichloroethylene (TCE) are environmental toxins with carcinogenic properties. The authors investigated associations between geographic clustering of CTCL incidence in the state of Georgia with benzene and TCE exposure. The statewide county-level incidence of CTCL within Georgia was obtained from the Georgia Cancer Registry for the years 1999 to 2015. Standardized incidence ratios (SIRs) were calculated by dividing observed cases by expected cases using national incidence rates by age, sex, and race. Clustering of CTCL was analyzed using spatial analyses. County-level concentrations of benzene and TCE between 1996 and 2014 were collected from the Environmental Protection Agency's National Air Toxics Assessment database. Linear regression analyses on CTCL incidence were performed comparing SIRs with levels of benzene and TCE by county. There was significant geographic clustering of CTCL in Georgia, particularly around Atlanta, which was correlated with an increased concentration of benzene and TCE exposure. Among the 4 most populous counties in Georgia, CTCL incidence was between 1.2 and 1.9 times higher than the state average, and benzene and TCE levels were between 2.9 and 8.8 times higher. The current results demonstrate nonrandom geographic clustering of CTCL incidence in Georgia. To the authors' knowledge, this is the first analysis to identify a correlation between geographic clustering of CTCL and environmental toxic exposures.

680: Adverse effects of benzene, toluene, ethylbenzene, and xylene air toxics on preterm birth

Air toxics include volatile organic compounds emitted from gasoline and industrial sites, known commonly as BTEX (benzene, toluene, ethylbenzene, and xylene). The effect of these air toxics on the risk of preterm birth (PTB) has not been studied. We sought to determine if rates of PTB differ by census-level variations in BTEX ambient exposures in Philadelphia and whether associations differed between medically-indicated (mPTB) compared to spontaneous PTB (sPTB). We analyzed data from a retrospective cohort (GeoBirth, n= 10,040). We analyzed associations of BTEX compounds exposure by census tract using EPA National Air Toxics Assessment data from 2014 with PTB. Manual chart review was performed to adjudicate each preterm birth (PTB) as either sPTB or mPTB. Each woman’s address was geocoded. We used mixed effects logistic regression models to estimate adjusted odds of PTB, sPTB and mPTB (vs. term births) adjusting for maternal age, race, parity, marital status, and insurance status. There were 10,040 live births, of which 11.1% were PTB, 6.6% were sPTB, and 4.5% were mPTB. Only mean benzene exposure was higher among women with all PTBs (0.696 mg/m3) versus term (0.693 mg/m3) (p = 0.0476). After adjustment for confounding variables, the odds ratio (OR) for PTB vs. term birth for benzene was 1.07 (95% CI 1.02-1.12); for toluene, OR 1.04 (95% CI 0.98-1.11); for ethylbenzenes, OR 1.07 (95% CI 1.00-1.14); and for xylenes, OR 1.06 (95% CI 0.99-1.14). We only found associations of BTEX compounds with sPTB (not mPTB); aORs: 1.16 (95% CI 1.07-1.26) for benzene, 1.16 (95% CI 1.05-1.29) for toluene, 1.20 (95% CI 1.08-1.32) for ethylbenzene, and 1.20 (95% CI 1.08-1.33) for xylene. This study found associations between BTEX air toxics and adverse pregnancy outcomes, specifically sPTB. The methods utilized highlight the importance of careful phenotyping of sPTB and mPTB. Notably, associations of environmental hazards with specific PTB phenotypes may be missed if all PTBs are considered as a single entity. Reducing exposures to air toxics may help to improve birth outcomes.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Combined association of BTEX and material hardship on ADHD-suggestive behaviours among a nationally representative sample of US children.

Previous research shows that environmental and social factors contribute to the development of attention-deficit/hyperactivity disorder (ADHD). To determine the relationship between early-life exposure to common ambient air pollutants (benzene, toluene, ethylbenzene, and xylene, also known as BTEX), household material hardship (a measure of socio-economic status), and ADHD-suggestive behaviours in kindergarten-age children. Pollutant exposure estimated from the 2002 National Air Toxics Assessment ateach child's residential ZIP code at enrolment was linked to the Early Childhood Longitudinal Study Birth Cohort (n=4650). Material hardship was assigned as a composite score of access to food, health care, and housing. Kindergarten teachers rated children's behaviours and activity in the classroom using a five-point Likert scale. Children with summary scores in the bottom decile were classified as displaying ADHD-suggestive behaviours. Logistic regression models were constructed to estimate the association between both BTEX exposure and material hardship on ADHD-suggestive behaviours. The odds of displaying ADHD-suggestive behaviours were greater in children with combined high-level exposure to BTEX and in those experiencing material hardship (odds ratio 1.54, 95% confidence interval [CI] 1.12, 2.11, and OR 2.12, 95% CI 1.25, 3.59, respectively), adjusting for covariates. These associations were stronger when restricting the study population to urban areas. There was no evidence of interaction between early life BTEX exposure and material hardship, although the effects of BTEX exposure were slightly greater in magnitude among those with higher material hardship scores. Children exposed to air toxics, material hardship, or both early in life are more likely to display signs of ADHD-suggestive behaviours as assessed by their kindergarten teachers. The associations between exposures to air pollution and to socio-economic hardship were observed in all children but were particularly strong in those living in urban areas.

Cancer risk from air toxics in relation to neighborhood isolation and sociodemographic characteristics: A spatial analysis of the St. Louis metropolitan area, USA

BackgroundA growing body of research has examined relationships between neighborhood characteristics and exposure to air toxics in the United States. However, a limited number of studies have addressed neighborhood isolation, a measure of spatial segregation. We investigated the spatial distribution of carcinogenic air toxics in the St. Louis metropolitan area and tested the hypothesis that neighborhood isolation and sociodemographic characteristics are associated with exposure to carcinogenic air toxics. MethodsWe obtained lifetime air toxics cancer risk data from the United States Environmental Protection Agency's National Air Toxic Assessment and sociodemographic data from the American Community Survey. We used geographic information systems to identify statistically significant clusters of census tracts with elevated all-site cancer risk due to air toxics in the St. Louis metropolitan area. Relative Risks (RR) were estimated for the association between neighborhood characteristics and air toxic hot spots. Using a local spatial isolation index to evaluate residential segregation, we also evaluated the association between neighborhood racial and economic isolation and air toxic hot spots. ResultsApproximately 14% (85 of the 615) of census tracts had elevated cancer risk due to air toxics (p < 0.01). These air toxic hot spots were independently associated with neighborhoods with high levels of poverty and unemployment and low levels of education. Census tracts with the highest levels of both racial isolation of Blacks and economic isolation of poverty were more likely to be located in air toxic hotspots than those with low combined racial and economic isolation (RR = 5.34; 95% CI = 3.10–9.22). ConclusionsThese findings provide strong evidence of unequal distribution of carcinogenic air toxics in the St. Louis metropolitan area. Study results may be used to inform public health efforts to eliminate sociodemographic inequalities in exposure to air pollutants.

Metallic air pollutants and breast cancer heterogeneity

BackgroundEmerging evidence suggests airborne metals may be associated with breast cancer risk. However, breast cancer is heterogenous and associations with heavy metals vary by subtype. Heavy metals possess both carcinogenic and xenoestrogenic properties which may be related to different tumor etiologies. Therefore, we tested for etiologic heterogeneity, using a case-series approach, to determine whether associations between residential airborne metal concentrations and breast cancer differed by tumor subtype. MethodsBetween 2005 and 2008, we enrolled incident breast cancer cases into the Breast Cancer Care in Chicago study. Tumor estrogen and progesterone receptors status was determined by medical record abstraction and confirmed immunohistochemically (N = 696; 147 ER/PR-negative). The 2002 USEPA's National Air Toxics Assessment census-tract estimates of metal concentrations (antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel and selenium) were matched to participants' residences of the same year. Adjusted logistic regression models were used to examine whether the airborne heavy metal associations differed by tumor ER/PR status. Principal component analysis was performed to assess associations by metal co-exposures. ResultsComparing the highest and lowest quintiles, higher concentrations of antimony (odds ratio[OR]: 1.8, 95% confidence interval[CI]: 0.9, 3.7, P-trend: 0.05), cadmium (OR: 2.3, 95% CI: 1.2, 4.4, P-trend: 0.04) and cobalt (OR: 2.0, 95% CI: 0.9, 4.4, P-trend: 0.04) were associated with ER/PR-negative breast cancer. Mixture analysis using principal components suggested co-exposures to multiple airborne heavy metals may drive associations with tumor receptor status. ConclusionsAmong women diagnosed with breast cancer, metallic air pollutants were associated with increased odds of developing ER/PR-negative breast cancer.

Simulation of airborne trace metals in fine particulate matter over North America

Trace metal distributions are of relevance to understand sources of fine particulate matter (PM2.5), PM2.5-related health effects, and atmospheric chemistry. However, knowledge of trace metal distributions is lacking due to limited ground-based measurements and model simulations. This study develops a simulation of 12 trace metal concentrations (Si, Ca, Al, Fe, Ti, Mn, K, Mg, As, Cd, Ni and Pb) over continental North America for 2013 using the GEOS-Chem chemical transport model. Evaluation of modeled trace metal concentrations with observations indicates a spatial consistency within a factor of 2. The spatial distribution of trace metal concentrations reflects their primary emission sources. Crustal element (Si, Ca, Al, Fe, Ti, Mn, K) concentrations are enhanced over the central US from anthropogenic fugitive dust and over the southwestern U.S. due to natural mineral dust. Heavy metal (As, Cd, Ni and Pb) concentrations are high over the eastern U.S. from industry. K is abundant in the southeast from biomass burning. High concentrations of Mg are observed along the coast from sea spray. The spatial pattern of PM2.5 mass is most strongly correlated with Pb, Ni, As and K due to their signature emission sources. Challenges remain in accurately simulating observed trace metal concentrations. Halving anthropogenic fugitive dust emissions in the 2011 National Air Toxic Assessment (NATA) inventory and doubling natural dust emissions in the default GEOS-Chem simulation was necessary to reduce biases in crustal element concentrations. A fivefold increase of anthropogenic emissions of As and Pb was necessary in the NATA inventory to reduce the national-scale bias versus observations by more than 80%, potentially reflecting missing sources.

Hazardous air pollutants and telomere length in the Sister Study.

Telomeres are vital for genomic integrity and telomere length has been linked to many adverse health outcomes. Some hazardous air pollutants, or air toxics, increase oxidative stress and inflammation, two possible determinants of shortened telomere length. No studies have examined air toxic-telomere length associations in a non-occupational setting. This study included 731 Sister Study participants (enrolled 2003-2007) who were randomly selected to assess telomere length in baseline blood samples. Multiplex qPCR was used to determine telomere to single copy gene (T/S) ratios. Census tract concentration estimates of 29 air toxics from the 2005 National Air Toxics Assessment were linked to baseline residential addresses. Air toxics were classified into tertile-based categories of the exposure. Multivariable linear regression was used to estimate β coefficients and 95% confidence intervals (CI) in single pollutant models. Multipollutant groups were identified with regression trees. The average T/S ratio was 1.24. Benzidine (T3vsT1 β= -0.08; 95% CI: -0.14, -0.01) and 1,4-dioxane (T3vsT1 β= -0.06; 95% CI: -0.13, 0.00) in particular, as well as carbon tetrachloride, chloroprene, ethylene dibromide, and propylene dichloride, were associated with shorter relative telomere length. Benzidine (p=0.02) and 1,4-dioxane (p=0.06) demonstrated some evidence of a monotonic trend. The regression tree identified age, BMI, physical activity, ethylene oxide, acrylonitrile, ethylidene dichloride, propylene dichloride, and styrene in multipollutant groups related to telomere length. In this first study of air toxics and telomere length in a non-occupational setting, several air toxics, particularly 1,4-dioxane and benzidine, were associated with shorter relative telomere length.

Maternal exposure to ambient cadmium levels, maternal smoking during pregnancy, and congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare musculoskeletal birth defect with a prevalence of 2.61 per 10,000 in the United States. There is limited evidence for ambient air pollutants in the etiology of CDH in humans. We investigated the role of maternal exposure to ambient cadmium as a risk factor for CDH (overall and stratified by isolated and non-isolated subtypes) in Florida and whether maternal smoking during pregnancy was an effect modifier of this association. We conducted a population-based, retrospective cohort study using data from the 1999-2012 Florida Birth Defects Registry linked to the National Air Toxic Assessment database. Analyses included chi-square tests; multilevel Poisson regression models to calculate measures of association between cadmium and CDH; and stratified analyses to examine effect modification by maternal smoking status. The study population consisted of 2,591,395 live births including 840 CDH cases. We did not find evidence for an association between maternal exposure to ambient cadmium concentration and CDH. We observed a 24% increased risk of CDH among isolated cases in the highest quartile of cadmium exposure (95% confidence interval [CI]: 1.00, 1.55). Although we were limited by small sample size for CDH cases, we found that among mothers who smoked during pregnancy, exposure to the highest quartile of cadmium was associated with more than two times higher risk for CDH among overall (95%CI: 1.04, 4.39) and isolated (95%CI: 1.07, 5.57) cases. Additional research is needed to elucidate the mechanism by which maternal ambient cadmium exposure may increase the risk of CDH in offspring, and the extent to which maternal smoking during pregnancy modifies this association.

Airborne mammary carcinogens and breast cancer risk in the Sister Study

IntroductionPotentially carcinogenic hazardous air pollutants (air toxics) have been inconsistently associated with breast cancer. Whether metabolic factors modify these associations is unknown. We studied 29 non-metallic air toxics classified as mammary gland carcinogens in animal studies in relation to breast cancer risk. MethodsParticipants included 49,718 women from the Sister Study. Census tract air toxic concentration estimates from the 2005 National Air Toxics Assessment were linked to enrollment residential addresses. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for individual air toxics were estimated using Cox regression. Body mass index (BMI) was considered a potential modifier. Relevant mixtures were identified using classification trees. ResultsOver follow-up (average = 8.4 years), 2975 women were newly diagnosed with breast cancer (invasive or ductal carcinoma in situ). Several air toxics, including methylene chloride, polycyclic organic matter, propylene dichloride, and styrene, were associated with increased risk. Of these, methylene chloride was most consistently associated with risk across multiple analyses. It was associated with overall (HRquintile 4vs1 = 1.21 (95%CI = 1.07–1.38)) and estrogen receptor positive (ER+) invasive breast cancer (HRquintile 4vs1 = 1.28 (95%CI = 1.08–1.52)) in individual pollutant models, although no dose-response was observed. Associations were stronger among overweight/obese (vs. non-overweight/obese) women (p < 0.05) for six air toxics. The classification tree identified combinations of age, methylene chloride, BMI, and four other toxics (propylene dichloride, ethylene dibromide, ethylidene dichloride, styrene) related to overall breast cancer. ConclusionsSome non-metallic air toxics, particularly methylene chloride, were associated with the hazard for overall and ER+ breast cancer. Overweight/obese women may be particularly susceptible to air toxics.

Lifetime cancer risks from hazardous air pollutants in US public school districts

BackgroundChildren are sensitive to the health impacts of environmental contaminants, but research assessing outdoor environmental exposures for children and schools is underdeveloped. There are no national-level studies examining geographical and...

Association of geographic clustering of cutaneous T-cell lymphoma in the state of Georgia with environmental exposure to benzene and trichloroethylene.

1551 Background: Geographic clustering of CTCL has been recently reported in large registries, but its association with environment factors is unknown. Benzene and trichloroethylene (TCE) are two common carcinogenic environmental toxins associated with hematological cancers. We investigated associations between geographic clustering of CTCL incidence in the state of Georgia with benzene and TCE exposure. Methods: We obtained county-level incidence of CTCL within Georgia from the Georgia Cancer Registry between 1999-2015. To account for the demographic structure in each county, standardized incidence ratios (SIR) were calculated by dividing the observed number of cases of CTCL in Georgia by the expected number of cases using national incidence rates by age, sex, and race. Using spatial analyses, we assessed for population-adjusted county-level clustering of SIRs. We also recorded county-level exposure concentration of benzene and TCE between 1996-2014 from the EPA’s National Air Toxics Assessment database. Linear regression analyses on CTCL incidence were performed comparing SIRs to exposure levels of benzene and TCE by county. Results: Our analyses demonstrated significant geographic clustering of CTCL in Georgia (Moran’s I statistic 0.0991, p-value = 0.022). Local spatial tests revealed several statistically significant hot spots throughout Georgia, particularly around Atlanta. This clustering was strongly correlated with benzene (R2 0.0824, p-value 0.0006) and TCE (R2 0.0614, p-value 0.0016) exposure concentration. Among the four most populous counties in Georgia (Cobb, Dekalb, Fulton, and Gwinnett) CTCL incidence was 1.7 to 2.7 times higher than the average county, and benzene and TCE exposure concentration was 3.0 to 6.3 times higher. Conclusions: These results demonstrate non-random geographic clustering of CTCL incidence in Georgia. This is the first analysis to correlate geographic clustering of CTCL with environmental toxic exposures, demonstrating a statistically significant correlation between environmental exposure to benzene and TCE and CTCL incidence within Georgia. [Table: see text]

Geospatial Correlation of Amyopathic Dermatomyositis With Fixed Sources of Airborne Pollution: A Retrospective Cohort Study.

Objective: Dermatomyositis (DM) may result from exogenous triggers, including airborne pollutants, in genetically susceptible individuals. The United States Environmental Protection Agency's 2011 National Air Toxics Assessment (NATA) models health risks associated with airborne emissions, available by ZIP code tabulation area (ZCTA). Important contributors include point (fixed), on-road, and secondary sources. The objective of this study was to investigate the geospatial distributions of DM and subtypes, classic DM (CDM) and clinically amyopathic DM (CADM), and their associations with airborne pollutants.Methods: This retrospective cohort study identified 642 adult DM patients from 336 unique ZCTAs. GeoDa v.1.10 was used to calculate global and local Moran's indices and generate local indicator of spatial autocorrelation (LISA) maps. All Moran's indices and LISA maps were permuted 999 times.Results: Univariate global Moran's indices for DM, CDM, and CADM prevalence were not significant, but LISA maps demonstrated differential local spatial clustering and outliers. CADM prevalence correlated with point sources (bivariate global Moran's index 0.071, pseudo-p = 0.018), in contrast to CDM (−0.0053, pseudo-p = 0.46). Bivariate global Moran's indices for DM, CDM, and CADM prevalence did not correlate with other airborne toxics, but bivariate LISA maps revealed local spatial clustering and outliers.Conclusion: Prevalence of CADM, but not CDM, is geospatially correlated with fixed sources of airborne emissions. This effect is small but significant and may support the hypothesis that triggering exposures influence disease phenotype. Important limitations are NATA data and ZCTA population estimates were collected from 2011 and ZCTA of residence may not have been where patients had greatest airborne pollutant exposure.

Association between Cadmium Air Exposure and Prostate Cancer Stage at Diagnosis

IntroductionThere is clear evidence that high levels of occupational exposure to cadmium (Cd) lead to a more aggressive prostate cancer (PC) tumor. At levels of exposure which are more relevant to the general population, there is disputing evidence as to whether Cd causes a PC tumor to become more aggressive. In this study, we assess the relationship between ambient exposure to air Cd and PC stage at diagnosis.MethodsWe collected outcome data from the Surveillance, Epidemiology, and End Results (SEER) for reported PC cases diagnosed from 2010 to 2014. PC stage at diagnosis was categorized as metastatic or localized. Exposure data was collected from the 2011 National Air Toxics Assessment (NATA) which was developed by the EPA to review air toxics in the United States. The total exposure concentration of Cd compounds in the air was a county‐level metric calculated by the EPA using weighted averages of air Cd concentration levels measured at various point emission sources. We calculated quintiles of Cd exposure concentration for ease of interpretation. Odds Ratios (OR) and 95% confidence intervals (CI) assessing the relationship between county‐level air Cd exposure and PC stage at diagnosis were calculated using multivariable logistic regression models. Analyses were adjusted for age at diagnosis, sociodemographic status, and overall air quality and were stratified by race.ResultsThe study cohort consisted of 234,991 PC cases from 594 counties reported by SEER. Of these cases, 92.5% were localized and 7.5% metastatic at diagnosis. Higher levels of air Cd exposure were associated with an increased likelihood of a PC case being metastatic at diagnosis. The adjusted odds ratios for the 80th percentile vs 20th percentile of Cd exposure were: all races (OR 1.030, CI 1.019 – 1.040), White (1.049, CI 1.037 – 1.062), Black (1.032, CI 1.0072 – 1.057), and other races (0.965, CI 0.925 – 1.0062).ConclusionHigher Cd air exposure concentration was associated with advanced PC stage at diagnosis with effects that vary somewhat by race. Since inhalation of Cd in the air only contributes to a small percentage of total Cd intake, further studies should be conducted to investigate the effects of other forms of Cd intake such as dietary and water exposures on PC aggressiveness.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Environmental Styrene Exposure and Sensory and Motor Function in Gulf Coast Residents.

Background:Although styrene is an established neurotoxicant at occupational exposure levels, its neurotoxicity has not been characterized in relation to general population exposures. Further, occupational research to date has focused on central nervous system impairment.Objective:We assessed styrene-associated differences in sensory and motor function among Gulf coast residents.Methods:We used 2011 National Air Toxics Assessment estimates of ambient styrene to determine exposure levels for 2,956 nondiabetic Gulf state residents enrolled in the Gulf Long-term Follow-up Study, and additionally measured blood styrene concentration in a subset of participants 1 to 2 y after enrollment (). Participants completed an enrollment telephone interview and a comprehensive test battery to assess sensory and motor function during a clinical follow-up exam 2 to 4 y later. Detailed covariate information was ascertained at enrollment via telephone interview. We used multivariate linear regression to estimate continuous differences in sensory and motor function, and log-binomial regression to estimate prevalence ratios for dichotomous outcomes. We estimated associations of both ambient and blood styrene exposures with sensory and motor function, independently for five unique tests.Results:Those participants in the highest 25% vs. lowest 75% of ambient exposure and those in the highest 10% vs. lowest 90% of blood styrene had slightly diminished visual contrast sensitivity. Mean vibrotactile thresholds were lower among those in the highest vs. lowest quartile of ambient styrene and the highest 10% vs. lowest 90% of blood styrene ( log microns; 95% CI: , and log microns; 95% CI: , , respectively). The highest vs. lowest quartile of ambient styrene was associated with significantly poorer postural stability, and (unexpectedly) with significantly greater grip strength.Discussion:We observed associations between higher styrene exposure and poorer visual, sensory, and vestibular function, though we did not detect associations with reduced voluntary motor system performance. Associations were more consistent for ambient exposures, but we also found notable associations with measured blood styrene. https://doi.org/10.1289/EHP3954

Predictors of residential mobility and its impact on air pollution exposure among children diagnosed with early childhood leukemia.

Epidemiology studies relying on one address to assign exposures over time share common methodological limitations in failing to account for mobility that may introduce potential exposure misclassification. Using Texas birth certificate and cancer registry data, we identified predictors of residential mobility among mothers of children diagnosed with early childhood leukemia in Texas from 1995 to 2011. We used U.S. Environmental Protection Agency (EPA) National Air Toxics Assessment data to estimate residential levels of benzene and 1,3-butadiene based on addresses at birth and diagnosis and applied mixed-effects ordinal logistic regression models to evaluate differences in exposure classification between the two time periods. In total, 55% of children moved from time of birth to diagnosis, although they generally did not move far (median distance moved was 8 km). Predictors of mobility, at delivery, included younger age, being unmarried and living in neighborhoods with high benzene levels, and, at diagnosis, increasing child's age and living in neighborhoods with low poverty rates. We observed that the odds of being assigned to a higher exposure quartile at diagnosis relative to the time of birth decreased by 31% for 1,3-butadiene (OR = 0.69, 95% CI 0.59-0.82) and by 12% for benzene (OR = 0.88, 95% CI 0.75, 1.05).

Airborne metals and polycyclic aromatic hydrocarbons in relation to mammographic breast density

BackgroundBreast density is strongly related to breast cancer. Identifying associations between environmental exposures and density may elucidate relationships with breast cancer. Metals and polycyclic aromatic hydrocarbons (PAHs) may influence breast density via oxidative stress or endocrine disruption.MethodsStudy participants (n = 222,581) underwent a screening mammogram in 2011 at a radiology facility in the Breast Cancer Surveillance Consortium. Zip code residential levels of airborne PAHs and metals (arsenic, cadmium, chromium, cobalt, lead, manganese, mercury, nickel, and selenium) were assessed using the 2011 EPA National Air Toxics Assessment. Breast density was measured using the Breast Imaging–Reporting and Data System (BI-RADS) lexicon. Logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CI) for the individual air toxics and dense breasts (BI-RADS 3 or 4). Weighted quantile sum (WQS) regression was used to model the association between the air toxic mixture and density.ResultsHigher residential levels of arsenic, cobalt, lead, manganese, nickel, or PAHs were individually associated with breast density. Comparing the highest to the lowest quartile, higher odds of having dense breasts were observed for cobalt (OR = 1.60, 95% CI 1.56–1.64) and lead (OR = 1.56, 95% CI 1.52–1.64). Associations were stronger for premenopausal women. The WQS index was associated with density overall (OR = 1.22, 95% CI 1.20–1.24); the most heavily weighted air toxics were lead and cobalt.ConclusionsIn this first study to evaluate the association between air toxics and breast density, women living in areas with higher concentrations of lead and cobalt were more likely to have dense breasts.

Utilization of the Maryland Environmental Justice Screening Tool: A Bladensburg, Maryland Case Study

Maryland residents’ knowledge of environmental hazards and their health effects is limited, partly due to the absence of tools to map and visualize distribution of risk factors across sociodemographic groups. This study discusses the development of the Maryland EJSCREEN (MD EJSCREEN) tool by the National Center for Smart Growth in partnership with faculty at the University of Maryland School of Public Health. The tool assesses environmental justice risks similarly to the U.S. Environmental Protection Agency’s (USEPA) EJSCREEN tool and California’s tool, CalEnviroScreen 3.0. We discuss the architecture and functionality of the tool, indicators of importance, and how it compares to USEPA’s EJSCREEN and CalEnviroScreen. We demonstrate the use of MD EJSCREEN through a case study on Bladensburg, Maryland, a town in Prince George’s County (PG) with several environmental justice concerns including air pollution from traffic and a concrete plant. Comparison reveals that environmental and demographic indicators in MD EJSCREEN most closely resemble those in EPA EJSCREEN, while the scoring is most similar to CalEnviroScreen. Case study results show that Bladensburg has a Prince George’s environmental justice score of 0.99, and that National Air Toxics Assessment (NATA) air toxics cancer risk is concentrated in communities of color.