An applied environmental justice framework for exposure science.

On the 30th anniversary of the Principles of Environmental Justice established at the First National People of Color Environmental Leadership Summit in 1991 (Principles of Environmental Justice), we continue to call for these principles to be more widely adopted. We propose an environmental justice framework for exposure science to be implemented by all researchers. This framework should be the standard and not an afterthought or trend dismissed by those who believe that science should not be politicized. Most notably, this framework should be centered on the community it seeks to serve. Researchers should meet with community members and stakeholders to learn more about the community, involve them in the research process, collectively determine the environmental exposure issues of highest concern for the community, and develop sustainable interventions and implementation strategies to address them. Incorporating community "funds of knowledge" will also inform the study design by incorporating the knowledge about the issue that community members have based on their lived experiences. Institutional and funding agency funds should also be directed to supporting community needs both during the "active" research phase and at the conclusion of the research, such as mechanisms for dissemination, capacity building, and engagement with policymakers. This multidirectional framework for exposure science will increase the sustainability of the research and its impact for long-term success.

Wood smoke black carbon from Indigenous traditional cultural activities in a subarctic Cree community.

Indoor concentrations of black carbon (BC) were measured when wood was burned for traditional cultural activities in a study in a Cree community located in subarctic Canada. The study also included an intervention using a propane-fuelled heater to mitigate in situ BC. Mass concentrations of BC were measured in a game-smoking tent for 39 days and in hunting cabins on the west coast of James Bay, Canada, for 8 days. Five-minute averaged BC mass concentration (N = 12,319) data were recorded and assessed using optimised noise-reduction averaging. Mean BC mass concentrations were lower in hunting cabins (mean = 8.25 micrograms per cubic metre (µg m-3)) and higher in the game-smoking tent (mean = 15.46 µg m-3). However, excessive BC peaks were recorded in the game-smoking tent (maximum = 3076.71 µg m-3) when the fire was stoked or loaded. The intervention with the propane heater in a hunting cabin yielded a 90% reduction in measured BC mass concentrations. We do not presume that exposure to BC is of concern in hunting cabins with appropriate wood-burning appliances that are well-sealed and vent outside. In game-smoking tents, we advise that persons take intermittent breaks outside of the tent for fresh air.

Addressing decontaminated respirators: Some methods appear to damage mask integrity and protective function.

Decontamination of N95 respirators is being used by clinicians in the face of a global shortage of these devices. Some treatments for decontamination, such as some vaporized hydrogen peroxide methods or ultraviolet methods, had no impact on respiratory performance, while other treatments resulted in substantial damage to masks.

Three Years of High Time-resolution Air Pollution Monitoring in the Complex Multi-source Harbor of New York and New Jersey.

In densely developed port areas with numerous emissions sources, relating measured air quality changes to emissions is challenging given the geographic density of sources without unique pollutant composition signatures. To better understand air quality during increasing emission controls at the Port of New York and New Jersey ("Port"), an air monitoring station was sited to minimize collinearity of sources along ordinal directions. The study area includes an international airport, interstate highway, port terminals and shipping lanes, and industrial sources, as well as typical urban emissions of a megacity. Because air flow travel time from sources to the monitor were usually much less than one hour, minute-by-minute, high-precision data were collected for three years (2013-2015) for sulfur dioxide (SO2), carbon monoxide (CO), oxides of nitrogen (NO, NO2), black carbon (BC), fine particulate matter (PM2.5), and meteorology (wind speed, wind direction, temperature, humidity). From summer 2014 to spring 2015, hourly metals data were also collected. A high degree of temporal variability was observed for pollutants associated with direct emissions, with highest hourly average coefficient of variation observed for NO (2.65), SO2 (1.45) and BC (1.21). Nonparametric trajectory analysis (NTA) was utilized to separate the source areas influencing the monitoring data and observe how they changed over time, with over 1.6 million trajectories computed in total. Comparing the last 5 quarters of the study to the first 5 quarters, concentrations at the monitoring site associated with three port-related geographic areas decreased by 34-41%, 11-17%, and 28-41% for SO2, NOx, and BC, respectively. Over the same period, indicators of shipping and cargo activity at the port remained relatively constant; therefore, a shift in emission factors is likely the cause of the change. This study demonstrates the value of high-time resolution, accurate monitoring data along with careful siting to understand source area influences.

Mobile monitoring of air and noise pollution in Philadelphia neighborhoods during 2017.

Mobile monitoring is a useful approach for measuring intra-urban variation of air pollution in urban environments. In this study, we used a mobile monitoring approach to study the spatial-temporal variability of air and noise pollution in urban neighborhoods of Philadelphia. During summer 2017, we used portable instruments to measure PM2.5, black carbon (BC), and noise levels along 5 km paths in four residential neighborhoods (Tioga, Mill Creek, Chestnut Hill, and Northern Liberties) and one commercial district (Center City) in Philadelphia, Pennsylvania, USA. A total of 62 sets of measurements were made at three different times of day (during morning rush hour, mid-afternoon, and during afternoon rush hour) from June 5 to July 7, 2017. Spatially, there was a significant difference in PM2.5 concentrations among the four residential neighborhoods. Overall, the Chestnut Hill neighborhood had the highest PM2.5 concentrations (13.25 ±â€¯6.89 µg/m3), followed by Tioga (9.58 ±â€¯4.83 µg/m3), Northern Liberties (7.02 ±â€¯4.17 µg/m3), and Mill Creek (3.9 ±â€¯4.5 µg/m3). There was temporal variability of pollutants depending on the neighborhood; Northern Liberties demonstrated the highest temporal variability in these data. The highest PM2.5 (18.86 ±â€¯3.17 mg/m3) was measured in the Chestnut Hill neighborhood during mid-afternoon. Mean PM2.5, BC, and noise levels based on mobile measurements at Philadelphia during summer 2017 were 8.41 ±â€¯4.31 µg/m3, 0.99 ±â€¯0.44 µg C/m3, and 62.01 ±â€¯3.20 dBA, respectively. Environmental noise showed the highest temporal variation of the monitored components for 3 time periods. In general, tree cover showed a weak and inconclusive association with particulate pollution levels.

Roadside Exposure and Inflammation Biomarkers among a Cohort of Traffic Police in Kathmandu, Nepal.

Air pollution is a major environmental problem in the Kathmandu Valley. Specifically, roadside and traffic-related air pollution exposure levels were found at very high levels exceeding Nepal air quality standards for daily PM2.5. In an exposure study involving traffic police officers, we collected 78 blood samples in a highly polluted spring season (16 February 2014⁻4 April 2014) and 63 blood samples in the less polluted summer season (20 July 2014⁻22 August 2014). Fourteen biomarkers, i.e., C-reactive protein (CRP), serum amyloid A (SAA), intracellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1), interferon gamma (IFN-γ), interleukins (IL1-ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13), and tumor necrosis factor (TNF-α) were analyzed in collected blood samples using proinflammatory panel 1 kits and vascular injury panel 2 kits. All the inflammatory biomarker levels were higher in the summer season than in the spring season, while particulate levels were higher in the spring season than in the summer season. We did not find significant association between 24-hour average PM2.5 or black carbon (BC) exposure levels with most of analyzed biomarkers for the traffic volunteers working and residing near busy roads in Kathmandu, Nepal, during 2014. Inflammation and vascular injury marker concentrations were generally higher in females, suggesting the important role of gender in inflammation biomarkers. Because of the small sample size of female subjects, further investigation with a larger sample size is required to confirm the role of gender in inflammation biomarkers.

Exposure to air pollutants in Vietnam: Assessing potential risk for tourists.

Tourism can form an important component of a nation's GDP, and Vietnam is among the most visited countries in Southeast Asia. Most studies on personal exposure focus on the general population, or occupational cohorts with exposure to specific pollutants. However, short-term exposure to air pollutants while visiting regions with high levels of air pollution can lead to acute health effects. A personal exposure study was conducted across three cities in Vietnam to estimate exposure to particulate matter (PM2.5) and black carbon for tourists. Measurements were conducted during the wet season in 2014 in Ho Chi Minh City, Da Lat and Nha Trang using portable instrumentation. Average 24-hr PM2.5 and BC exposures were estimated as 18.9±9.24 and 3.41±1.33µg/m3 and among the three cities, Ho Chi Minh was found to have the highest PM2.5 concentrations. Environmental tobacco smoke, commuting and street food stands were found to contribute to highest levels of exposure to PM2.5 and BC across all cities.

PM2.5 exposure in highly polluted cities: A case study from New Delhi, India.

Personal exposure (PE) to air pollutants is driven by a combination of pollutant concentrations in indoor and outdoor environments, and time-activity pattern of individuals. The objectives of this study were to estimate personal exposure to PM2.5 and black carbon (BC), and assess the representability of ambient air quality monitoring stations to serve as surrogates for PE in New Delhi. Personal exposure to air pollutants (PM2.5-PE and BCPE) was measured using portable, battery-operated instruments (PM2.5- pDR1500 and BC- microAethalometer AE51) in a small cohort of healthy adults (n=12 in summer, n=6 in winter) with no occupational exposure. Average PM2.5-PE and BCPE (µg/m3) were 53.9±136 and 3.71±4.29 respectively, in summer and 489.2±209.2 and 23.3±14.9 respectively, in winter. Activities associated with highest exposure levels were cooking and indoor cleaning for PM2.5, and commuting for BC. Within transport microenvironments, autorickshaws were found to be the most polluted, and lowest BC exposure was registered in public buses. Comparison of fixed-site ambient monitoring data showed a higher correlation with personal exposure dataset in winter compared to summer (r2 of 0.51 (winter) and 0.21 (summer); 51% (winter) and 20% (summer)). This study highlights the need for detailed assessment of PE to air pollutants in Indian cities, and calls for a denser network of monitoring stations for better exposure assessment.

Evaluating the efficacy of cloth facemasks in reducing particulate matter exposure.

Inexpensive cloth masks are widely used in developing countries to protect from particulate pollution albeit limited data on their efficacy exists. This study examined the efficiency of four types of masks (three types of cloth masks and one type of surgical mask) commonly worn in the developing world. Five monodispersed aerosol sphere size (30, 100, and 500 nm, and 1 and 2.5 µm) and diluted whole diesel exhaust was used to assess facemask performance. Among the three cloth mask types, a cloth mask with an exhaust valve performed best with filtration efficiency of 80-90% for the measured polystyrene latex (PSL) particle sizes. Two styles of commercially available fabric masks were the least effective with a filtration efficiency of 39-65% for PSL particles, and they performed better as the particle size increased. When the cloth masks were tested against lab-generated whole diesel particles, the filtration efficiency for three particle sizes (30, 100, and 500 nm) ranged from 15% to 57%. Standard N95 mask performance was used as a control to compare the results with cloth masks, and our results suggest that cloth masks are only marginally beneficial in protecting individuals from particles<2.5 µm. Compared with cloth masks, disposable surgical masks are more effective in reducing particulate exposure.

Exposure science in an age of rapidly changing climate: challenges and opportunities.

Climate change is anticipated to alter the production, use, release, and fate of environmental chemicals, likely leading to increased uncertainty in exposure and human health risk predictions. Exposure science provides a key connection between changes in climate and associated health outcomes. The theme of the 2015 Annual Meeting of the International Society of Exposure Science-Exposures in an Evolving Environment-brought this issue to the fore. By directing attention to questions that may affect society in profound ways, exposure scientists have an opportunity to conduct "consequential science"-doing science that matters, using our tools for the greater good and to answer key policy questions, and identifying causes leading to implementation of solutions. Understanding the implications of changing exposures on public health may be one of the most consequential areas of study in which exposure scientists could currently be engaged. In this paper, we use a series of case studies to identify exposure data gaps and research paths that will enable us to capture the information necessary for understanding climate change-related human exposures and consequent health impacts. We hope that paper will focus attention on under-developed areas of exposure science that will likely have broad implications for public health.

Respiratory Effects of High Levels of Particulate Exposure in a Cohort of Traffic Police in Kathmandu, Nepal.

OBJECTIVES: To investigate the traffic-related PM2.5 and black carbon (BC) exposures and assess their health effects. METHODS: Personal exposure to PM2.5 and BC levels were monitored in a cohort of traffic police (n = 53) at six locations in Kathmandu Valley, Nepal during dry and rainy seasons in 2014. RESULTS: Mean on-road exposure levels of PM2.5 and BC ranged from 34 to 193 µg/m(3) and 12 to 28 µgC/m(3), respectively, and were associated with an acute decline in lung function. Use of N95 mask had clear benefits reducing the lung function decreases after occupational exposures when masks were worn for just half of a workweek. CONCLUSIONS: Exposure of high levels of PM2.5 was associated with reduced lung function. Increased levels of BC exposure led to reduced lung function in non-smoking traffic officers with non-normal spirometry observations.

Exposure to particulate matter in India: A synthesis of findings and future directions.

Air pollution poses a critical threat to human health with ambient and household air pollution identified as key health risks in India. While there are many studies investigating concentration, composition, and health effects of air pollution, investigators are only beginning to focus on estimating or measuring personal exposure. Further, the relevance of exposures studies from the developed countries in developing countries is uncertain. This review summarizes existing research on exposure to particulate matter (PM) in India, identifies gaps and offers recommendations for future research. There are a limited number of studies focused on exposure to PM and/or associated health effects in India, but it is evident that levels of exposure are much higher than those reported in developed countries. Most studies have focused on coarse aerosols, with a few studies on fine aerosols. Additionally, most studies have focused on a handful of cities, and there are many unknowns in terms of ambient levels of PM as well as personal exposure. Given the high mortality burden associated with air pollution exposure in India, a deeper understanding of ambient pollutant levels as well as source strengths is crucial, both in urban and rural areas. Further, the attention needs to expand beyond the handful large cities that have been studied in detail.

Mining in subarctic Canada: airborne PM2.5 metal concentrations in two remote First Nations communities.

Airborne particulate matter arising from upwind mining activities is a concern for First Nations communities in the western James Bay region of Ontario, Canada. Aerosol chemical components were collected in 2011 from two communities in northern Ontario. The chemical and mass concentration data of particulate matter collected during this study shows a significant difference in PM2.5 in Attawapiskat compared to Fort Albany. Elemental profiles indicate enhanced levels of some tracers thought to arise from mining activities, such as, K, Ni, and crustal materials. Both communities are remote and isolated from urban and industrial pollution sources, however, Attawapiskat First Nation has significantly enhanced levels of particulate matter, and it is likely that some of this arises from upwind mining activities.

Repeated measures of inflammation, blood pressure, and heart rate variability associated with traffic exposures in healthy adults.

BACKGROUND: Previous human exposure studies of traffic-related air pollutants have demonstrated adverse health effects in human populations by comparing areas of high and low traffic, but few studies have utilized microenvironmental monitoring of pollutants at multiple traffic locations while looking at a vast array of health endpoints in the same population. We evaluated inflammatory markers, heart rate variability (HRV), blood pressure, exhaled nitric oxide, and lung function in healthy participants after exposures to varying mixtures of traffic pollutants. METHODS: A repeated-measures, crossover study design was used in which 23 healthy, non-smoking adults had clinical cardiopulmonary and systemic inflammatory measurements taken prior to, immediately after, and 24 hours after intermittent walking for two hours in the summer months along three diverse roadways having unique emission characteristics. Measurements of PM2.5, PM10, black carbon (BC), elemental carbon (EC), and organic carbon (OC) were collected. Mixed effect models were used to assess changes in health effects associated with these specific pollutant classes. RESULTS: Minimal associations were observed with lung function measurements and the pollutants measured. Small decreases in BP measurements and rMSSD, and increases in IL-1ß and the low frequency to high frequency ratio measured in HRV, were observed with increasing concentrations of PM2.5 EC. CONCLUSIONS: Small, acute changes in cardiovascular and inflammation-related effects of microenvironmental exposures to traffic-related air pollution were observed in a group of healthy young adults. The associations were most profound with the diesel-source EC.

Organic aerosols associated with the generation of reactive oxygen species (ROS) by water-soluble PM2.5.

We compare the relative toxicity of various organic aerosol (OA) components identified by an aerosol mass spectrometer (AMS) based on their ability to generate reactive oxygen species (ROS). Ambient fine aerosols were collected from urban (three in Atlanta, GA and one in Birmingham, AL) and rural (Yorkville, GA and Centerville, AL) sites in the Southeastern United States. The ROS generating capability of the water-soluble fraction of the particles was measured by the dithiothreitol (DTT) assay. Water-soluble PM extracts were further separated into the hydrophobic and hydrophilic fractions using a C-18 column, and both fractions were analyzed for DTT activity and water-soluble metals. Organic aerosol composition was measured at selected sites using a high-resolution time-of-flight AMS. Positive matrix factorization of the AMS spectra resolved the organic aerosol into isoprene-derived OA (Isop_OA), hydrocarbon-like OA (HOA), less-oxidized oxygenated OA, (LO-OOA), more-oxidized OOA (MO-OOA), cooking OA (COA), and biomass burning OA (BBOA). The association of the DTT activity of water-soluble PM2.5 (WS_DTT) with these factors was investigated by linear regression techniques. BBOA and MO-OOA were most consistently linked with WS_DTT, with intrinsic water-soluble activities of 151 ± 20 and 36 ± 22 pmol/min/µg, respectively. Although less toxic, MO-OOA was most widespread, contributing to WS_DTT activity at all sites and during all seasons. WS_DTT activity was least associated with biogenic secondary organic aerosol. The OA components contributing to WS_DTT were humic-like substances (HULIS), which are abundantly emitted in biomass burning (BBOA) and include highly oxidized OA from multiple sources (MO-OOA). Overall, OA contributed approximately 60% to the WS_DTT activity, with the remaining probably from water-soluble metals, which were mostly associated with the hydrophilic WS_DTT fraction.

Non-sulfate sulfur in fine aerosols across the United States: Insight for organosulfate prevalence.

We investigated the discrepancies in long-term sulfur measurements from 2000 to 2012 by two separate speciation methods, X-ray fluorescence (XRF) spectroscopy and ion chromatography (IC) across the United States (334 sites). Overall, there was a good correlation between sulfur measurements by XRF spectroscopy and IC (R ≥ 0.90 for most of the sites). However, the inorganic sulfate measured by ion chromatography was not sufficient to account for all the sulfur measured by XRF spectroscopy at many of the sites. Discrepancies were observed with the high ratios of sulfur measured by XRF spectroscopy to that by IC. Such high ratios also exhibited seasonal variation, and differed across land use types; significant differences occurred at locations classified as forest, agriculture, and mobile, but not in locations classified as commercial, desert, industrial, and residential. On average, the excess, or non-sulfate, sulfur (unmeasured organic sulfur or other inorganic species of sulfur) was variable and observed as high as ~13% of organic carbon and ~2% of PM2.5. The contribution of such assumed organosulfur was larger in the eastern region than other geographical locations in the United States. Besides the temporal and spatial trends, the additional sulfur was found to be related to other factors such as aerosol acidity and emission sources. The results suggest that these unmeasured sulfur species could have significant contribution to aerosol burden, and the understanding of these could help to control PM2.5 levels and to assess other effects of sulfur aerosols.

Acute high-level exposure to WTC particles alters expression of genes associated with oxidative stress and immune function in the lung.

First responders (FR) present at Ground Zero in the first 72 h after the World Trade Center (WTC) collapsed have progressively exhibited significant respiratory injuries. The few toxicology studies performed to date evaluated effects from just fine (< 2.5 µm) WTC dusts; none examined health effects/toxicities from atmospheres bearing larger particle sizes, despite the fact the majority (> 96%) of dusts were > 10 µm and most FR likely entrained dusts by mouth breathing. Using a system that generated/delivered supercoarse (10-53 µm) WTC dusts to F344 rats (in a manner that mimicked FR exposures), this study sought to examine potential toxicities in the lungs. In this exploratory study, rats were exposed for 2 h to 100 mg WTC dust/m(3) (while under isoflurane [ISO] anesthesia) or an air/ISO mixture; this dose conservatively modeled likely exposures by mouth-breathing FR facing ≈750-1000 mg WTC dust/m(3). Lungs were harvested 2 h post-exposure and total RNA extracted for subsequent global gene expression analysis. Among the > 1000 genes affected by WTC dust (under ISO) or ISO alone, 166 were unique to the dust exposure. In many instances, genes maximally-induced by the WTC dust exposure (relative to in naïve rats) were unchanged/inhibited by ISO only; similarly, several genes maximally inhibited in WTC dust rats were largely induced/unchanged in rats that received ISO only. These outcomes reflect likely contrasting effects of ISO and the WTC dust on lung gene expression. Overall, the data show that lungs of rats exposed to WTC dust (under ISO) - after accounting for any impact from ISO alone - displayed increased expression of genes related to lung inflammation, oxidative stress, and cell cycle control, while several involved in anti-oxidant function were inhibited. These changes suggested acute inflammogenic effects and oxidative stress in the lungs of WTC dust-exposed rats. This study, thus, concludes that a single very high exposure to WTC dusts could potentially have adversely affected the respiratory system - in terms of early inflammatory and oxidative stress processes. As these changes were not compared with other types of dusts, the uniqueness of these WTC-mediated effects remains to be confirmed. It also still remains to be determined if these effects might have any relevance to chronic lung pathologies that became evident among FR who encountered the highest dust levels on September 11, 2001 and the 2 days thereafter. Ongoing studies using longer-range post-exposure analyses (up to 1-year or more) will help to determine if effects seen here on genes were acute, reversible, or persistent, and associated with corresponding histopathologic/biochemical changes in situ.

Black carbon and particulate matter (PM2.5) concentrations in New York City's subway stations.

The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 µg/m(3), with 1 min average peaks >100 µg/m(3), while real time PM2.5 levels ranged from 35 to 200 µg/m(3). Mean EC levels ranged from 9 to 12.5 µg/m(3). At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 µg/m(3), respectively. This study shows that both BC soot and PM levels in NYC's subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted.