Pregnant Women's Exposure to Household Air Pollution in Rural Bangladesh: A Feasibility Study for Poriborton: The CHANge Trial.

The use of liquefied petroleum gas (LPG) for cooking is a strategy to reduce household air pollution (HAP) exposure and improve health. We conducted this feasibility study to evaluate personal exposure measurement methods to representatively assess reductions in HAP exposure. We enrolled 30 pregnant women to wear a MicroPEM for 24 h to assess their HAP exposure when cooking with a traditional stove (baseline) and with an LPG stove (intervention). The women wore the MicroPEM an average of 77% and 69% of the time during the baseline and intervention phases, respectively. Mean gravimetric PM2.5 mass and black carbon concentrations were comparable during baseline and intervention. Temporal analysis of the MicroPEM nephelometer data identified high PM2.5 concentrations in the afternoon, late evening, and overnight during the intervention phase. Likely seasonal sources present during the intervention phase were emissions from brick kiln and rice parboiling facilities, and evening kerosene lamp and mosquito coil use. Mean background adjusted PM2.5 concentrations during cooking were lower during intervention at 71 µg/m3, versus 105 µg/m3 during baseline. Representative real-time personal PM2.5 concentration measurements supplemented with ambient PM2.5 measures and surveys will be a valuable tool to disentangle external sources of PM2.5, other indoor HAP sources, and fuel-sparing behaviors when assessing the HAP reduction due to intervention with LPG stoves.

Children's Particulate Matter Exposure Characterization as Part of the New Hampshire Birth Cohort Study.

As part of the New Hampshire Birth Cohort Study, children 3 to 5 years of age participated in a personal PM2.5 exposure study. This paper characterizes the personal PM2.5 exposure and protocol compliance measured with a wearable sensor. The MicroPEM™ collected personal continuous and integrated measures of PM2.5 exposure and compliance data on 272 children. PM2.5, black carbon (BC), and brown carbon tobacco smoke (BrC-ETS) exposure was measured from the filters. We performed a multivariate analysis of woodstove presence and other factors that influenced PM2.5, BC, and BrC exposures. We collected valid exposure data from 258 of the 272 participants (95%). Children wore the MicroPEM for an average of 46% of the 72-h period, and over 80% for a 2-day, 1-night period (with sleep hours counted as non-compliance for this study). Elevated PM2.5 exposures occurred in the morning, evening, and overnight. Median PM2.5, BC, and BrC-ETS concentrations were 8.1 µg/m3, 3.6 µg/m3, and 2.4 µg/m3. The combined BC and BrC-ETS mass comprised 72% of the PM2.5. Woodstove presence, hours used per day, and the primary heating source were associated with the children's PM2.5 exposure and air filters were associated with reduced PM2.5 concentrations. Our findings suggest that woodstove smoke contributed significantly to this cohort's PM2.5 exposure. The high sample validity and compliance rate demonstrated that the MicroPEM can be worn by young children in epidemiologic studies to measure their PM2.5 exposure, inform interventions to reduce the exposures, and improve children's health.

Commuter types identified using clustering and their associations with source-specific PM2.5.

Traffic-related fine particulate matter air pollution (tr-PM2.5) has been associated with adverse health outcomes such as cardiopulmonary morbidity and mortality, with in-vehicle tr-PM2.5 exposure contributing to total personal pollution exposure. Trip characteristics, including time of day, day of the week, and traffic congestion, are associated with in-vehicle PM2.5 exposures. We hypothesized that some commuter characteristics, such as whether commuters travel primarily during rush hour, would also be associated with increased tr-PM2.5 exposures. The commute data consisted of unscripted personal vehicle trips of 46 commuters in the Washington, D.C. metro area over 48-h, with a total of 320 trips. We identified commuter types using sparse K-means clustering, which identifies the hours throughout the day important for clustering commuters. Source-specific PM2.5 over 48 h was estimated using Positive Matrix Factorization. Linear regression was used to estimate differences in source-specific PM2.5 by commuter cluster. Two commuter clusters were identified using the clustering approach: rush hour commuters, who primarily travelled during rush hour, and sporadic commuters, who travelled throughout the day. The hours given the largest weights by sparse K-means were 7-8 a.m. and 6-7 p.m., corresponding to peak travel times. Integrated black carbon (BC) was higher for rush hour commuters (median = 3.1 µg/m3 (IQR = 1.5)) compared to sporadic commuters (2.0 µg/m3 (IQR = 1.9)). Mobile PM2.5, consisting primarily of tailpipe emissions and brake/tire wear, was also higher for rush hour commuters (2.9 µg/m3 (IQR = 1.6)) compared to sporadic commuters (2.1 µg/m3 (IQR = 2.4)), though this difference was not statistically significant in regression models. Estimated differences between commuter types for secondary/mixed PM2.5 and road salt PM2.5 were smaller. Further research may elucidate whether commuter characteristics are an efficient way to identify individuals with highest tr-PM2.5 exposures associated with commuting and to develop effective mitigation strategies.

Estimating exposure to traffic-related PM2.5 for women commuters using vehicle and personal monitoring.

Exposure to traffic-related fine particulate matter air pollution (tr-PM2.5) has been associated with adverse health outcomes including preterm birth and low birthweight. In-vehicle exposure to tr-PM2.5 can contribute substantially to total tr-PM2.5 exposure. Because average commuting habits of women differ from men, a research gap is estimating in-vehicle tr-PM2.5 exposures for women commuters. For 46 women commuters in the Washington, D.C. metro area, we measured personal exposure to PM2.5 during all vehicle trips taken in a 48-h sampling period. We also measured 48-h integrated PM2.5 chemical constituents including black carbon and zinc. We identified trip times using vehicle monitors, specifically on-board diagnostics data loggers and dashboard cameras. For 386 trips, we estimated associations between PM2.5 exposure and trip characteristics using linear mixed models accounting for participant, day, and time of day. Additionally, we estimated associations between rush hour trip PM2.5 and 48-h integrated PM2.5 chemical constituents using linear models. Exposure to PM2.5 during trips was 1.9 µg/m3 (95% confidence interval (CI): 0.9, 2.9) higher than non-trip exposures and rush hour trip exposures were 3.2 µg/m3 (95% CI: 1.8, 4.6) higher than non-trip exposures on average. We did not find differences in PM2.5 exposure by trip length. Although concentrations of tr-PM2.5 chemical constituents were generally positively associated with rush hour trip PM2.5, associations were weak indicating that other settings contribute to total tr-PM2.5 exposure. Our study demonstrates the utility of combining vehicle monitors and personal PM2.5 monitors for estimating personal exposure to tr-PM2.5. Future work will investigate whether additional data collected by vehicle monitors, such as traffic and speed, can be leveraged to better understand tr-PM2.5 exposure among commuters.

Exposure to Potentially Harmful E-Cigarette Emissions via Vape Tricks: Protocol for a Mixed-Methods Study.

BACKGROUND: The number of adolescents and adults using e-cigarettes, referred to as vaping, has dramatically increased. E-cigarettes can be used to perform vape tricks by inhaling and exhaling the e-cigarette aerosol in patterns to create visual effects or large clouds. To create these effects, the puffing patterns associated with vape tricks may be different than standard ad-lib e-cigarette usage. The prevalence of vape tricks and the harm associated with exposure to e-cigarette emissions when performing vape tricks is currently unknown. OBJECTIVE: Our objectives are to characterize duration, heart rate, respiratory rate, tidal volume, minute volume, and physical activity metrics associated with the performance of vape tricks and to characterize the emission of e-cigarettes when performing vape tricks in a manner suitable to inform novel exposure modeling. METHODS: The study will recruit e-cigarette users with a history of performing vape tricks. Data collection will occur in two different sessions. In the first session, participants will be asked to puff on their e-cigarette as they normally would for 20 minutes. The second session will be a vape tricks session, where users will be asked to perform a series of up to five different vape tricks with their e-cigarette. Data will be collected through screener surveys, in-person interviews, video recordings, a personal exposure monitor, and a biometric garment. RESULTS: Data analysis is pending and scheduled to take place in the fall of 2019. CONCLUSIONS: This study will be used to assess the feasibility of using a biometric garment to complement environmental and observational data. The approach may provide greater insight into the health risks of performing vape tricks compared to typical e-cigarette use. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/12304.

Dietary intakes of pesticides based on community duplicate diet samples.

The calculation of dietary intake of selected pesticides was accomplished using food samples collected from individual representatives of a defined demographic community using a community duplicate diet approach. A community of nine participants was identified in Apopka, FL from which intake assessments of organophosphate (OP) and pyrethroid pesticides were made. From these nine participants, sixty-seven individual samples were collected and subsequently analyzed by gas chromatography/mass spectrometry. Measured concentrations were used to estimate dietary intakes for individuals and for the community. Individual intakes of total OP and pyrethroid pesticides ranged from 6.7 to 996 ng and 1.2 to 16,000 ng, respectively. The community intake was 256 ng for OPs and 3430 ng for pyrethroid pesticides. The most commonly detected pesticide was permethrin, but the highest overall intake was of bifenthrin followed by esfenvalerate. These data indicate that the community in Apopka, FL, as represented by the nine individuals, was potentially exposed to both OP and pyrethroid pesticides at levels consistent with a dietary model and other field studies in which standard duplicate diet samples were collected. Higher levels of pyrethroid pesticides were measured than OPs, which is consistent with decreased usage of OPs. The diversity of pyrethroid pesticides detected in food samples was greater than expected. Continually changing pesticide usage patterns need to be considered when determining analytes of interest for large scale epidemiology studies. The Community Duplicate Diet Methodology is a tool for researchers to meet emerging exposure measurement needs that will lead to more accurate assessments of intake which may enhance decisions for chemical regulation. Successfully determining the intake of pesticides through the dietary route will allow for accurate assessments of pesticide exposures to a community of individuals, thereby significantly enhancing the research benefit realized from epidemiological exposure studies.

Development and preparation of lead-containing paint films and diagnostic test materials.

Lead in paint continues to be a threat to children's health in cities across the United States, which means there is an ongoing need for testing and analysis of paint. This ongoing analytical effort and especially development of new methods continue to drive the need for diagnostic testing materials that provide the analytical challenges of real-world paints. To this end, 31 different types of paint test materials were developed and prepared. Preparation of the materials included development of lead-containing paint films yielding an overall relative standard error for one individual test sample being less than 10%. The 31 diagnostic test materials prepared with these paint films included two lead pigments; lead concentrations from nominally 0 to 2.0 mg lead/cm(2) (0 to 5% lead by weight); overlayers of both "lead-free," oil-based and water-based paints; Al, Ba, and Mg as potential chemical interferents; red and black potential color interferents; and substrates of wood, metal, masonry, and plaster. These materials challenge each step in method development and evaluation, including paint sample collection and preparation, lead extraction, and measurement of solubilized lead. When the materials were used to test performance of a new lead-in-paint testing method based on extraction using a rotor/stator method and measurement using turbidimetry, the results agreed to within ±20% of the expected lead values for 30 out of 31 of the diagnostic test materials, thereby demonstrating their levels of quality and utility.

Community duplicate diet methodology: a new tool for estimating dietary exposures to pesticides.

An observational field study was conducted to assess the feasibility of a community duplicate diet collection method; a dietary monitoring tool that is population-based. The purpose was to establish an alternative procedure to duplicate diet sampling that would be more efficient for a large, defined population, e.g., in the National Children's Study (NCS). Questionnaire data and food samples were collected in a residence so as not to lose the important component of storage, preparation, and handling in a contaminated microenvironment. The participants included nine Hispanic women of child bearing age living in Apopka, FL, USA. Foods highly consumed by Hispanic women were identified based on national food frequency questionnaires and prioritized by permethrin residue concentrations as measured for the Pesticide Data Program. Participants filled out questionnaires to determine if highly consumed foods were commonly eaten by them and to assess the collection protocol for the food samples. Measureable levels of permethrin were found in 54% of the samples. Questionnaire responses indicated that the collection of the community duplicate diet was feasible for a defined population.

Field turbidity method for the determination of lead in acid extracts of dried paint.

Lead, which can be found in old paint, soil, and dust, has been clearly shown to have adverse health effects on the neurological systems of both children and adults. As part of an ongoing effort to reduce childhood lead poisoning, the US Environmental Protection Agency promulgated the Lead Renovation, Repair, and Painting Program (RRP) rule requiring that paint in target housing built prior to 1978 be tested for lead before any renovation, repair, or painting activities are initiated. This rule has led to a need for a rapid, relatively easy, and an inexpensive method for measuring lead in paint. This paper presents a new method for measuring lead extracted from paint that is based on turbidimetry. This method is applicable to paint that has been collected from a surface and extracted into 25% (v/v) of nitric acid. An aliquot of the filtered extract is mixed with an aliquot of solid potassium molybdate in 1 M ammonium acetate to form a turbid suspension of lead molybdate. The lead concentration is determined using a portable turbidity meter. This turbidimetric method has a response of approximately 0.9 NTU per microg lead per mL extract, with a range of 1-1000 Nephelometric Turbidity Units (NTUs). Precision at a concentration corresponding to the EPA-mandated decision point of 1 mg of lead per cm(2) is <2%. This method is insensitive to the presence of other metals common to paint, including Ba(2+), Ca(2+), Mg(2+), Fe(3+), Co(2+), Cu(2+), and Cd(2+), at concentrations of 10 mg mL(-1) or to Zn(2+) at 50 mg mL(-1). Analysis of 14 samples from six reference materials with lead concentrations near 1 mg cm(-2) yielded a correlation to inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analysis of 0.97, with an average bias of 2.8%. Twenty-four sets of either 6 or 10 paint samples each were collected from different locations in old houses, a hospital, tobacco factory, and power station. Half of each set was analyzed using rotor/stator-25% (v/v) nitric acid extraction with measurement using the new turbidimetric method, and the other half was analyzed using microwave extraction and measurement by ICP-AES. The average relative percent difference between the turbidimetric method and the ICP-AES method for the 24 sets measured as milligrams of lead per cm(2) is -0.63 +/- 32.5%; the mean difference is -2.1 +/- 7.0 mg lead per cm(2). Non-parametric and parametric statistical tests on these data showed no difference in the results for the two procedures. At the federal regulated level of 1 mg of lead per cm(2) paint, this turbidimetric method meets the performance requirements for EPA's National Lead Laboratory Accreditation Program (NLLAP) of accuracy within +/-20% and has the potential to meet the performance specifications of EPA's RRP rule.

Rapid new methods for paint collection and lead extraction.

Chronic exposure of children to lead can result in permanent physiological impairment. In adults, it can cause irritability, poor muscle coordination, and nerve damage to the sense organs and nerves controlling the body. Surfaces coated with lead-containing paints are potential sources of exposure to lead. In April 2008, the U.S. Environmental Protection Agency (EPA) finalized new requirements that would reduce exposure to lead hazards created by renovation, repair, and painting activities, which disturb lead-based paint. On-site, inexpensive identification of lead-based paint is required. Two steps have been taken to meet this challenge. First, this paper presents a new, highly efficient method for paint collection that is based on the use of a modified wood drill bit. Second, this paper presents a novel, one-step approach for quantitatively grinding and extracting lead from paint samples for subsequent lead determination. This latter method is based on the use of a high-revolutions per minute rotor with stator to break up the paint into approximately 50 micron-size particles. Nitric acid (25%, v/v) is used to extract the lead in <3 minutes. Recoveries are consistently >95% for real-world paints, National Institute of Standards and Technology's standard reference materials, and audit samples from the American Industrial Hygiene Association's Environmental Lead Proficiency Analytical Testing Program. This quantitative extraction procedure, when paired with quantitative paint sample collection and lead determination, may enable the development of a lead paint test kit that will meet the specifications of the final EPA rule.