Health benefits of decreases in on-road transportation emissions in the United States from 2008 to 2017.

Decades of air pollution regulation have yielded enormous benefits in the United States, but vehicle emissions remain a climate and public health issue. Studies have quantified the vehicle-related fine particulate matter (PM2.5)-attributable mortality but lack the combination of proper counterfactual scenarios, latest epidemiological evidence, and detailed spatial resolution; all needed to assess the benefits of recent emission reductions. We use this combination to assess PM2.5-attributable health benefits and also assess the climate benefits of on-road emission reductions between 2008 and 2017. We estimate total benefits of $270 (190 to 480) billion in 2017. Vehicle-related PM2.5-attributable deaths decreased from 27,700 in 2008 to 19,800 in 2017; however, had per-mile emission factors remained at 2008 levels, 48,200 deaths would have occurred in 2017. The 74% increase from 27,700 to 48,200 PM2.5-attributable deaths with the same emission factors is due to lower baseline PM2.5 concentrations (+26%), more vehicle miles and fleet composition changes (+22%), higher baseline mortality (+13%), and interactions among these (+12%). Climate benefits were small (3 to 19% of the total). The percent reductions in emissions and PM2.5-attributable deaths were similar despite an opportunity to achieve disproportionately large health benefits by reducing high-impact emissions of passenger light-duty vehicles in urban areas. Increasingly large vehicles and an aging population, increasing mortality, suggest large health benefits in urban areas require more stringent policies. Local policies can be effective because high-impact primary PM2.5 and NH3 emissions disperse little outside metropolitan areas. Complementary national-level policies for NOx are merited because of its substantial impacts-with little spatial variability-and dispersion across states and metropolitan areas.

Childhood pneumonia in Beijing: Associations and interactions among selected demographic and environmental factors.

Among infectious diseases, pneumonia is the greatest cause of mortality in children less than 5 years old. Approximately 27% of Beijing's 3-8 year-old children have had pneumonia at least once. The sole reservoir of pneumonia pathogens is the human nasopharynx. We investigated associations and interactions among two kinds of environmental risk factors: i) airborne pathogens, namely closed bedroom window and shared bedroom and ii) pollutants, namely traffic pollution and environmental tobacco smoke (ETS). We evaluated breastfeeding's (BF) protective value against childhood pneumonia. The database consists of responses to a questionnaire in a cross-sectional study. Crude and adjusted Odds Ratios were assessed independently for each risk factor. Combinations of the studied risk factors were analyzed using multivariate logistic regression. Risk factors were evaluated for interactions on the additive scale using the metrics Relative Excess Risk due to Interaction (RERI), Attributable Proportion (AP) and Synergy Index (S). All independent risk factors were significant for children's pneumonia. We also found evidence of possible synergistic interaction between pairs of risk factors that was stronger when one of the risk factors was a closed bedroom window. Remarkably, window opening was associated with reduced risk of pneumonia for children living near heavy traffic pollution. Longer duration BF was more protective than shorter, and exclusive BF was more protective than partial BF against childhood pneumonia. In conclusion, low ventilation (closed bedroom windows), shared bedroom, ETS, and traffic exposure were associated with increased risk of pneumonia. Exclusive BF for more than six months had the greatest protective value against pneumonia.

In situ psycho-cognitive assessments support self-determined urban green exercise time.

Prescribed nature walks frequently yield improvements to mood and cognition as observed in experimental studies. Research that uses real life settings such as self-determined time exercising outdoors for restorative health benefits may more accurately elicit effects than time-specified study protocols. This study examined in situ psycho-cognitive outcomes of routine walks in urban greenspace to test the concept that self-set exposure duration and not context alone is related to magnitude of psycho-cognitive benefit. Pre-post measurements taken on a diverse participant pool of individuals walking in urban parks and recruited on random days over a two-week period found significant associations between outdoor activity duration and cognitive and mood improvements. Greater outdoor walking duration linearly predicted stronger processing speeds but non-linearly in tests of other cognitive domains. Results of fixed effects model for mean mood change following green exercise show outdoor walking influenced mood change at highest levels of significance, even after accounting for individual level variability in duration. Mood improved for all durations of outdoor walking under a random effects model with high significance. Untethering fixed intervals of outdoor exercise from formal study design revealed briefer but more frequent nature engagement aligned with nature affinity. The influence of unmeasured factors, e.g., nature affinity or restorative conditioning, for prescriptive durations of urban green exercise merits further investigation toward designing wellbeing interventions directed at specific urban populations.

Home is Where the Pipeline Ends: Characterization of Volatile Organic Compounds Present in Natural Gas at the Point of the Residential End User.

The presence of volatile organic compounds (VOCs) in unprocessed natural gas (NG) is well documented; however, the degree to which VOCs are present in NG at the point of end use is largely uncharacterized. We collected 234 whole NG samples across 69 unique residential locations across the Greater Boston metropolitan area, Massachusetts. NG samples were measured for methane (CH4), ethane (C2H6), and nonmethane VOC (NMVOC) content (including tentatively identified compounds) using commercially available USEPA analytical methods. Results revealed 296 unique NMVOC constituents in end use NG, of which 21 (or approximately 7%) were designated as hazardous air pollutants. Benzene (bootstrapped mean = 164 ppbv; SD = 16; 95% CI: 134-196) was detected in 95% of samples along with hexane (98% detection), toluene (94%), heptane (94%), and cyclohexane (89%), contributing to a mean total concentration of NMVOCs in distribution-grade NG of 6.0 ppmv (95% CI: 5.5-6.6). While total VOCs exhibited significant spatial variability, over twice as much temporal variability was observed, with a wintertime NG benzene concentration nearly eight-fold greater than summertime. By using previous NG leakage data, we estimated that 120-356 kg/yr of annual NG benzene emissions throughout Greater Boston are not currently accounted for in emissions inventories, along with an unaccounted-for indoor portion. NG-odorant content (tert-butyl mercaptan and isopropyl mercaptan) was used to estimate that a mean NG-CH4 concentration of 21.3 ppmv (95% CI: 16.7-25.9) could persist undetected in ambient air given known odor detection thresholds. This implies that indoor NG leakage may be an underappreciated source of both CH4 and associated VOCs.

Metals dust in workers' homes and potential for take home in the Greater Boston area: Pilot study.

Toxic metals such as lead, cadmium, arsenic, are present at construction worksites. From work, metals can easily, unintentionally be transported to homes of workers, contaminating living spaces and affecting others including children, known as "take-home exposure." Focus has been given to minimizing lead take-home exposure but less is known about other metals. This pilot study aims to better understand the sources and predictors of metals in the home primarily of construction workers (n = 21), but also explore other workers potentially exposed [janitorial (n = 4) and auto repair (n = 2) jobs]. Greater Boston workers were recruited in 2018-2019 through collaboration with community-based organizations and worker unions serving low-income/immigrant workers. During a home visit, a dust vacuum sample was collected, a worker questionnaire was administered, and home observations were performed to determine factors that could affect home metals concentration. Thirty elements were analyzed in the dust via inductively coupled plasma coupled to atomic emission and mass spectrometry. We performed univariable and multivariable models, potential predictive factors, and multivariable mixed-effect regression analyses combining metals. Arsenic, chromium, copper, lead, manganese, nickel, and tin, commonly found in construction, were higher in construction workers' home dust compared to other workers, although not statistically significant. Sociodemographic/work/home-related variables affected home metals dust concentrations. Various work-related factors were associated with higher metal dust levels, for example: no work locker vs. locker (nickel ratio of means or ROM = 4.2, p < 0.05); mixing vs. no mixing work/personal items (nickel ROM = 1.6, p < 0.05); dusty vs. no dusty at work (copper ROM = 3.1, p < 0.05); not washing vs. washing hands after work (manganese ROM = 1.4, p < 0.05); not changing vs. changing clothes after work (cadmium ROM = 6.9, p < 0.05; copper ROM = 3.6, p < 0.05). Mixed effect regression confirmed statistical significance, which suggests a likelihood of metal mixtures carrying a "take-home" potential. Lead home interventions should evaluate other metals exposure reduction.

Indoor humidity levels and associations with reported symptoms in office buildings.

Moderate indoor relative humidity (RH) levels (i.e., 40%-60%) may minimize transmission and viability of some viruses, maximize human immune function, and minimize health risks from mold, yet uncertainties exist about typical RH levels in offices globally and about the potential independent impacts of RH levels on workers' health. To examine this, we leveraged one year of indoor RH measurements (which study participants could view in real time) in 43 office buildings in China, India, Mexico, Thailand, the United Kingdom, and the United States, and corresponding self-report symptom data from 227 office workers in a subset of 32 buildings. In the buildings in this study, 42% of measurements during 9:00 - 17:00 on weekdays were less than 40% RH and 7% exceeded 60% RH. Indoor RH levels tended to be lower in less tropical regions, in winter months, when outdoor RH or temperature was low, and late in the workday. Furthermore, we also found statistically significant evidence that higher indoor RH levels across the range of 14%-70% RH were associated with lower odds of reporting dryness or irritation of the throat and skin among females and unusual fatigue among males in models adjusted for indoor temperature, country, and day of year.

Tradeoffs between ventilation, air mixing, and passenger density for the airborne transmission risk in airport transportation vehicles.

Airport transportation vehicles, such as buses, aerotrains, and shuttles, provide important passenger transfer services in airports. This study quantitatively investigated COVID-19 aerosol infection risk and identified acceptable operational conditions, such as passenger occupancy rates and duration of rides, given the performance of vehicle ventilation. The greatest risk to the largest number of passengers is from an index case whose exhaled breath would take the longest time to exit the vehicle. The study identified such a case based on ventilation patterns, and it tracked the spread of viral aerosols (5 µm) by using the Wells-Riley equation to predict aerosol infection risk distribution. These distributions allowed a definition of an imperfect mixing degree (δ) as the ratio of actual risk and the calculated risk under a perfect mixing condition, and further derived regression equations to predict δ in the far-field (FF) and near-field (NF) of each passenger. These results revealed an order of magnitude higher aerosol infection risk in NF than in FF. For example, with a ventilation rate of 58 ACH (air changes per hour) and a 45% occupancy rate, unmasked passengers should stay up to 15 min in the bus and 35 min in the shuttle to limit infection risk in NF within 10%. These also indicate that masking is an important and effective risk reduction measure in transportation vehicles, especially important in NF. Overall, the analysis of imperfect air mixing allows direct comparison of risks in different transportation vehicles and a structured approach to development of policy recommendations.

Factors affecting lead dust in construction workers' homes in the Greater Boston Area.

Lead is a known reproductive, developmental, and neurological toxicant. Workers with a high likelihood of being exposed to lead at work may inadvertently transport lead home from work, known as "take-home exposure." This is concerning for many workers for whom a workplace intervention is not feasible because their worksites and employers often change, rendering centralized strategies insufficient. This study aimed to better understand the connection between lead in the home of workers living with children and work in construction (n = 23), while other occupations were used as a comparison group (janitorial n = 5, autobody n = 2). Thirty workers living in disadvantaged communities in the Greater Boston area were recruited in 2018-2019 through collaboration with non-profits and worker unions with expertise working with low-income or immigrant workers. Construction workers that performed renovations, bridge constructions, welding, metal work, and demolitions were prioritized during recruitment. During a visit to their residences, a worker questionnaire was administered, and observations and a dust vacuumed sample of the home were collected. Factors predicting lead in home dust were explored by a bivariate analysis and a multivariable regression model. We found lead in homes' dust in the range of 20-8,310 ppm. Homes of construction workers generally had higher and more variable lead dust concentrations (mean 775, max 8,300 ppm) than autobody and janitor worker homes combined (mean 296, max 579 ppm). Five of the construction workers' home lead dust concentrations exceeded US guidelines for yard soil in children's play areas of 400 ppm, and were similar to other studies of homes near lead smelters, superfund sites, or in the Boston area in the early 1990s, pointing to disparities relating to work. Results from the multivariable regression model suggest that lead dust in homes of workers was associated with sociodemographic-, home-, and work-related factors, and pointed to overlapping vulnerabilities; however, a larger sample size is needed to verify findings. Results provide evidence that work-related factors are important to consider when assessing home exposures, and that take-home exposures for workers in lead high-risk jobs such as construction may be an important source of exposure in the home prime for public health intervention at work, home, and community levels.

The Effects of Ventilation and Filtration on Indoor PM2.5 in Office Buildings in Four Countries.

Fine particulate matter (PM2.5) is an airborne pollutant associated with negative acute and chronic human health outcomes. Although the majority of PM2.5 research has focused on outdoor exposures, people spend the majority of their time indoors, where PM2.5 of outdoor origin can penetrate. In this work, we measured indoor PM2.5 continuously for one year in 37 urban commercial offices with mechanical or mixed-mode ventilation in China, India, the United Kingdom, and the United States. We found that indoor PM2.5 concentrations were generally higher when and where outdoor PM2.5 was elevated. In India and China, mean workday indoor PM2.5 levels exceeded the World Health Organization's 24-hour exposure guideline of 25 µg/m3 about 17% and 27% of the time, respectively. Our statistical models found evidence that the operation of mechanical ventilation systems could mitigate the intrusion of outdoor PM2.5: during standard work hours, a 10 µg/m3 increase in outdoor PM2.5 was associated with 19.9% increase in the expected concentration of indoor PM2.5 (p<0.0001), compared to a larger 23.4% increase during non-work hours (p<0.0001). Finally, our models found that using filters with ratings of MERV 13-14 or MERV 15+ was associated with a 30.9% (95% CI: -55.0%, +6.2%) or 39.4% (95% CI: -62.0%, -3.4%) reduction of indoor PM2.5, respectively, compared to filters with lower MERV 7-12 ratings. Our results demonstrate the potential efficacy of mechanical ventilation with efficient filtration as a public health strategy to protect workers from PM2.5 exposure, particularly where outdoor levels of PM2.5 are elevated.

The Influence of Heat on Daily Police, Medical, and Fire Dispatches in Boston, Massachusetts: Relative Risk and Time-Series Analyses.

Objectives. To examine the impact of extreme heat on emergency services in Boston, MA.Methods. We conducted relative risk and time series analyses of 911 dispatches of the Boston Police Department (BPD), Boston Emergency Medical Services (BEMS), and Boston Fire Department (BFD) from November 2010 to April 2014 to assess the impact of extreme heat on emergency services.Results. During the warm season, there were 2% (95% confidence interval [CI] = 0%, 5%) more BPD dispatches, 9% (95% CI = 7%, 12%) more BEMS dispatches, and 10% (95% CI = 5%, 15%) more BFD dispatches on days when the maximum temperature was 90°F or higher, which remained consistent when we considered multiple days of heat. A 10°F increase in daily maximum temperature, from 80° to 90°F, resulted in 1.016, 1.017, and 1.002 times the expected number of daily BPD, BEMS, and BFD dispatch calls, on average, after adjustment for other predictors.Conclusions. The burden of extreme heat on local emergency medical and police services may be agency-wide, and impacts on fire departments have not been previously documented.Public Health Implications. It is important to account for the societal burden of extreme heat impacts to most effectively inform climate change adaptation strategies and planning.

Effects of biophilic interventions in office on stress reaction and cognitive function: A randomized crossover study in virtual reality.

Biophilia hypothesis suggests humans have an innate connection to nature which may affect our health and productivity. Yet we currently live in a world that is rapidly urbanizing with people spending most of their time indoors. We designed a randomized crossover study to let 30 participants experience three versions of biophilic design in simulated open and enclosed office spaces in virtual reality (VR). Throughout the VR session, we measured blood pressure, heart rate, heart rate variability, and skin conductance level and administered cognitive tests to measure their reaction time and creativity. Compared to the base case, participants in three spaces with biophilic elements had consistently lower level of physiological stress indicators and higher creativity scores. In addition, we captured the variation in the intensity of virtual exposure to biophilic elements by using eye-tracking technology. These results suggest that biophilic interventions could help reduce stress and improve creativity. Moreover, those effects are related to both the types of biophilic elements and may be different based on the workspace type (open vs enclosed). This research demonstrates that VR-simulated office spaces are useful in differentiating responses to two configurations and among biophilic elements.

Stress and Health in Nursing Students: The Nurse Engagement and Wellness Study.

BACKGROUND: Evidence suggests that behavioral, social, and environmental factors may modify the effects of life stress on health and performance of new nurses as they transition to hospitals. OBJECTIVES: The aim of this study was to describe the methods of a project designed to investigate the role of social, behavioral, and environmental factors in modifying the adverse effects of stress on new nurses and to discuss demographic, health, and life stress characteristics of the cohort at baseline. METHODS: A prospective cohort design was used to conduct a comprehensive assessment of health endpoints, life stress, behaviors, personal traits, social factors, indicators of engagement and performance, and environmental exposures in nursing students. Adjusted odds ratios and analyses of covariance were used to examine associations between these factors at baseline. RESULTS: Health indicators in the cohort were comparable or better than in the broader United States population, and lifetime stress exposure was lower than among students from other majors. Exposure to more lifetime stressors was associated with greater risk for various health conditions, including hypertension, diabetes, and depression. Conversely, better social, environmental, behavioral, and personal profiles were associated with protective effects for the same health conditions. DISCUSSION: These data comprehensively summarize the lives of predominately Hispanic nursing students and highlight risk and resilience factors associated with their health and well-being. The findings are timely, as the nursing field diversifies in preparation to care for a diverse and aging population. Comprehensively assessing stress-health relationships among student nurses ought to inform the policies, practices, and curricula of nursing schools to better prepare nurses to thrive in the often-strenuous healthcare environment.

Reduced cognitive function during a heat wave among residents of non-air-conditioned buildings: An observational study of young adults in the summer of 2016.

BACKGROUND: In many regions globally, buildings designed for harnessing heat during the cold exacerbate thermal exposures during heat waves (HWs) by maintaining elevated indoor temperatures even when high ambient temperatures have subdued. While previous experimental studies have documented the effects of ambient temperatures on cognitive function, few have observed HW effects on indoor temperatures following subjects' habitual conditions. The objective was to evaluate the differential impact of having air conditioning (AC) on cognitive function during a HW among residents of AC and non-AC buildings using a prospective observational cohort study. METHODS: We followed 44 students (mean age = 20.2 years; SD = 1.8 years) from a university in the Greater Boston area, Massachusetts in the United States living in AC (n = 24) and non-AC (n = 20) buildings before, during, and after a HW. Two cognition tests were self-administered daily for a period of 12 days (July 9-July 20, 2016), the Stroop color-word test (STROOP) to assess selective attention/processing speed and a 2-digit, visual addition/subtraction test (ADD) to evaluate cognitive speed and working memory. The effect of the HW on cognitive function was evaluated using difference-in-differences (DiD) modelling. FINDINGS: Mean indoor temperatures in the non-AC group (mean = 26.3°C; SD = 2.5°C; range = 19.6-30.4°C) were significantly higher (p < 0.001) than in the AC group (mean = 21.4°C; SD = 1.9°C; range = 17.5-25.0°C). DiD estimates show an increase in reaction time (STROOP = 13.4%, p < 0001; ADD = 13.3%, p < 0.001) and reduction in throughput (STROOP = -9.9%, p < 0.001; ADD = -6.3%, p = 0.08) during HWs among non-AC residents relative to AC residents at baseline. While ADD showed a linear relationship with indoor temperatures, STROOP was described by a U-shaped curve with linear effects below and above an optimum range (indoor temperature = 22°C-23°C), with an increase in reaction time of 16 ms/°C and 24 ms/°C for STROOP and ADD, respectively. Cognitive tests occurred right after waking, so the study is limited in that it cannot assess whether the observed effects extended during the rest of the day. Although the range of students' ages also represents a limitation of the study, the consistent findings in this young, healthy population might indicate that greater portions of the population are susceptible to the effects of extreme heat. CONCLUSIONS: Cognitive function deficits resulting from indoor thermal conditions during HWs extend beyond vulnerable populations. Our findings highlight the importance of incorporating sustainable adaptation measures in buildings to preserve educational attainment, economic productivity, and safety in light of a changing climate.

Flame Retardant Chemicals in College Dormitories: Flammability Standards Influence Dust Concentrations.

Furniture flammability standards are typically met with chemical flame retardants (FRs). FRs can migrate out of products into dust and are linked to cancer, neurological impairment, and endocrine disruption. We collected 95 dust samples from dormitory common areas and student rooms on two U.S. college campuses adhering to two different furniture flammability standards: Technical Bulletin 117 (TB117) and Technical Bulletin 133 (TB133). Because TB133 requires furniture to withstand a much-more-demanding test flame than TB117, we hypothesized that spaces with TB133 furniture would have higher levels of FRs in dust. We found all 47 targeted FRs, including 12 polybrominated diphenyl ether (PBDE) congeners, 19 other brominated FRs, 11 phosphorus FRs (PFRs), 2 Dechlorane-Plus (DP) isomers, and 3 hexabromocyclododecane (HBCDD) isomers in the 95 dust samples. We measured the highest reported U.S. concentrations for a number of FRs, including BDE 209 (up to 990 000 ng/g), which may be used to meet the TB133 standard. We prioritized 16 FRs and analyzed levels in relation to flammability standard as well as presence and age of furniture and electronics. Adherence to TB133 was associated with higher concentrations of BDE 209, decabromodiphenylethane (DBDPE), DPs, and HBCDD compared to adherence to TB117 in univariate models (p < 0.05). Student dormitory rooms tended to have higher levels of some FRs compared to common rooms, likely a result of the density of furniture and electronics. As flammability standards are updated, it is critical to understand their impact on exposure and health risks.

The Impact of Working in a Green Certified Building on Cognitive Function and Health.

Thirty years of public health research have demonstrated that improved indoor environmental quality is associated with better health outcomes. Recent research has demonstrated an impact of the indoor environment on cognitive function. We recruited 109 participants from 10 high-performing buildings (i.e. buildings surpassing the ASHRAE Standard 62.1-2010 ventilation requirement and with low total volatile organic compound concentrations) in five U.S. cities. In each city, buildings were matched by week of assessment, tenant, type of worker and work functions. A key distinction between the matched buildings was whether they had achieved green certification. Workers were administered a cognitive function test of higher order decision-making performance twice during the same week while indoor environmental quality parameters were monitored. Workers in green certified buildings scored 26.4% (95% CI: [12.8%, 39.7%]) higher on cognitive function tests, controlling for annual earnings, job category and level of schooling, and had 30% fewer sick building symptoms than those in non-certified buildings. These outcomes may be partially explained by IEQ factors, including thermal conditions and lighting, but the findings suggest that the benefits of green certification standards go beyond measureable IEQ factors. We describe a holistic "buildingomics" approach for examining the complexity of factors in a building that influence human health.

Geographical Inequalities and Social and Environmental Risk Factors for Under-Five Mortality in Ghana in 2000 and 2010: Bayesian Spatial Analysis of Census Data.

BACKGROUND: Under-five mortality is declining in Ghana and many other countries. Very few studies have measured under-five mortality-and its social and environmental risk factors-at fine spatial resolutions, which is relevant for policy purposes. Our aim was to estimate under-five mortality and its social and environmental risk factors at the district level in Ghana. METHODS AND FINDINGS: We used 10% random samples of Ghana's 2000 and 2010 National Population and Housing Censuses. We applied indirect demographic methods and a Bayesian spatial model to the information on total number of children ever born and children surviving to estimate under-five mortality (probability of dying by 5 y of age, 5q0) for each of Ghana's 110 districts. We also used the census data to estimate the distributions of households or persons in each district in terms of fuel used for cooking, sanitation facility, drinking water source, and parental education. Median district 5q0 declined from 99 deaths per 1,000 live births in 2000 to 70 in 2010. The decline ranged from <5% in some northern districts, where 5q0 had been higher in 2000, to >40% in southern districts, where it had been lower in 2000, exacerbating existing inequalities. Primary education increased in men and women, and more households had access to improved water and sanitation and cleaner cooking fuels. Higher use of liquefied petroleum gas for cooking was associated with lower 5q0 in multivariate analysis. CONCLUSIONS: Under-five mortality has declined in all of Ghana's districts, but the cross-district inequality in mortality has increased. There is a need for additional data, including on healthcare, and additional environmental and socioeconomic measurements, to understand the reasons for the variations in mortality levels and trends.

PBDE flame retardants, thyroid disease, and menopausal status in U.S. women.

BACKGROUND: Women have elevated rates of thyroid disease compared to men. Environmental toxicants have been implicated as contributors to this dimorphism, including polybrominated diphenyl ethers (PBDEs), flame retardant chemicals that disrupt thyroid hormone action. PBDEs have also been implicated in the disruption of estrogenic activity, and estrogen levels regulate thyroid hormones. Post-menopausal women may therefore be particularly vulnerable to PBDE induced thyroid effects, given low estrogen reserves. The objective of this study was to test for an association between serum PBDE concentrations and thyroid disease in women from the United States (U.S.), stratified by menopause status. METHODS: Serum PBDE concentrations (BDEs 47, 99, 100 and 153) from the National Health and Examination Survey (NHANES) and reports on thyroid problems were available in the NHANES 2003-2004 cycle. Odds ratios (ORs) were calculated using multivariate logistic regression models accounting for population-weighted survey techniques and controlling for age, body mass index (BMI), education, smoking, alcohol consumption and thyroid medication. Menopause status was obtained by self-reported absence of menstruation in the previous 12 months and declared menopause. RESULTS: Women in the highest quartile of serum concentrations for BDEs 47, 99, and 100 had increased odds of currently having thyroid disease (ORs: 1.5, 1.8, 1.5, respectively) compared to the reference group (1st and 2nd quartiles combined); stronger associations were observed when the analysis was restricted to postmenopausal women (ORs: 2.2, 3.6, 2.0, respectively). CONCLUSION: Exposure to BDEs 47, 99, and 100 is associated with thyroid disease in a national sample of U.S. women, with greater effects observed post-menopause, suggesting that the disruption of thyroid signaling by PBDEs may be enhanced by the altered estrogen levels during menopause.

A longitudinal study of mercury exposure associated with consumption of freshwater fish from a reservoir in rural south central USA.

Methylmercury (MeHg) exposure through fish consumption is a worldwide health concern. Saltwater fish account for most dietary MeHg exposure in the general U.S. population, but less is known about seasonal variations in MeHg exposure and fish consumption among millions of freshwater anglers. This longitudinal study examined associations between MeHg exposure and fish consumption in a rural, low-income population relying on a freshwater reservoir (Oklahoma, USA) for recreational and subsistence fishing. We interviewed 151 participants, primarily anglers and their families, seasonally for one year using 90-day recall food frequency questionnaires to assess general and species-specific fish consumption, and tested hair biomarker samples for total mercury (THg hair). Mean THg hair was 0.27 µg/g (n=595, range: 0.0044-3.1 µg/g), with 4% of participants above U.S. EPA's guideline for women of childbearing age and children. Mean fish consumption was 58 g/d (95% CI: 49-67 g/d), within the range previously reported for recreational freshwater anglers and above the national average. Unlike the general U.S. population, freshwater species contributed the majority of fish consumption (69%) and dietary Hg exposure (60%) among participants, despite relatively low THg in local fish. THg hair increased with fish consumption, age, and education, and was higher among male participants and the lowest in winter. Our results suggest that future studies of anglers should consider seasonality in fish consumption and MeHg exposure and include household members who share their catch. Efforts to evaluate benefits of reducing Hg emissions should consider dietary patterns among consumers of fish from local freshwater bodies.

Environmental conditions in low-income urban housing: clustering and associations with self-reported health.

OBJECTIVES: We explored prevalence and clustering of key environmental conditions in low-income housing and associations with self-reported health. METHODS: The Health in Common Study, conducted between 2005 and 2009, recruited participants (n = 828) from 20 low-income housing developments in the Boston area. We interviewed 1 participant per household and conducted a brief inspection of the unit (apartment). We created binary indexes and a summed index for household exposures: mold, combustion by-products, secondhand smoke, chemicals, pests, and inadequate ventilation. We used multivariable logistic regression to examine the associations between each index and household characteristics and between each index and self-reported health. RESULTS: Environmental problems were common; more than half of homes had 3 or more exposure-related problems (median summed index = 3). After adjustment for household-level demographics, we found clustering of problems in site (P < .01) for pests, combustion byproducts, mold, and ventilation. Higher summed index values were associated with higher adjusted odds of reporting fair-poor health (odds ratio = 2.7 for highest category; P < .008 for trend). CONCLUSIONS: We found evidence that indoor environmental conditions in multifamily housing cluster by site and that cumulative exposures may be associated with poor health.