Quantifying Multipollutant Health Impacts Using the Environmental Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE): A Case Study in Atlanta, Georgia.

BACKGROUND: Air pollution risk assessments do not generally quantify health impacts using multipollutant risk estimates, but instead use results from single-pollutant or copollutant models. Multipollutant epidemiological models account for pollutant interactions and joint effects but can be computationally complex and data intensive. Risk estimates from multipollutant studies are therefore challenging to implement in the quantification of health impacts. OBJECTIVES: Our objective was to conduct a case study using a developmental multipollutant version of the Environmental Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) to estimate the health impact associated with changes in multiple air pollutants using both a single and multipollutant approach. METHODS: BenMAP-CE was used to estimate the change in the number of pediatric asthma emergency department (ED) visits attributable to simulated changes in air pollution between 2011 and 2025 in Atlanta, Georgia, applying risk estimates from an epidemiological study that examined short-term single-pollutant and multipollutant (with and without first-order interactions) exposures. Analyses examined individual pollutants (i.e., ozone, fine particulate matter, carbon monoxide, nitrogen dioxide (NO2), sulfur dioxide, and particulate matter components) and combinations of these pollutants meant to represent shared properties or predefined sources (i.e., oxidant gases, secondary pollutants, traffic, power plant, and criteria pollutants). Comparisons were made between multipollutant health impact functions (HIF) and the sum of single-pollutant HIFs for the individual pollutants that constitute the respective pollutant groups. RESULTS: Photochemical modeling predicted large decreases in most of the examined pollutant concentrations between 2011 and 2025 based on sector specific (i.e., source-based) estimates of growth and anticipated controls. Estimated number of avoided asthma ED visits attributable to any given multipollutant group were generally higher when using results from models that included interaction terms in comparison with those that did not. We estimated the greatest number of avoided pediatric asthma ED visits for pollutant groups that include NO2 (i. e., criteria pollutants, oxidants, and traffic pollutants). In models that accounted for interaction, year-round estimates for pollutant groups that included NO2 ranged from 27.1 [95% confidence interval (CI): 1.6, 52.7; traffic pollutants] to 55.4 (95% CI: 41.8, 69.0; oxidants) avoided pediatric asthma ED visits. Year-round results using multipollutant risk estimates with interaction were comparable to the sum of the single-pollutant results corresponding to most multipollutant groups [e.g., 52.9 (95% CI: 43.6, 62.2) for oxidants] but were notably lower than the sum of the single-pollutant results for some pollutant groups [e.g., 77.5 (95% CI: 66.0, 89.0) for traffic pollutants]. DISCUSSION: Performing a multipollutant health impact assessment is technically feasible but computationally complex. It requires time, resources, and detailed input parameters not commonly reported in air pollution epidemiological studies. Results estimated using the sum of single-pollutant models are comparable to those quantified using a multipollutant model. Although limited to a single study and location, assessing the trade-offs between a multipollutant and single-pollutant approach is warranted. https://doi.org/10.1289/EHP12969.

Applying a multistate survival model to explore the role of fine particles in promoting frailty in the Medicare cohort.

Fine particle pollution is a well-established risk to human health. Observational epidemiology generally treats events as though they are independent of one another and so do not examine the role air pollution may play in promoting the progression of disease. Multistate survival models account for the complex pathway of disease to death. We employ a multistate survival model to characterize the role of chronic exposure to PM2.5 in affecting the rate at which Medicare beneficiaries transition to first hospitalization for cardiovascular disease and then subsequently death. We use an open cohort of Medicare beneficiaries and PM2.5 concentrations estimated with photochemical model predictions, satellite-based observations, land-use data, and meteorological variables. The multistate model included three transitions: (1) entry to cardiovascular hospital admission; (2) entry to death; and (3) cardiovascular hospital admission to death. The transition intensity was modeled using a Cox proportional hazards model. For a 1 µg/m3 increase in annual mean PM2.5, we estimate a nationally pooled hazard ratio of 1.022 (95% confidence interval [CI] = 1.018, 1.025) for the transition from entry to first cardiovascular hospital admission; 1.054 (95% CI = 1.039, 1.068) for the transition from entry to death; 1.036 (95% CI = 1.027, 1.044) for the transition from first cardiovascular hospital admission to death. The hazard ratios exhibited some heterogeneity within each of nine climatological regions and for each of the three transitions. We find evidence for the role of PM in both promoting chronic illness and increasing the subsequent risk of death.

Self-reported health impacts of do-it-yourself air cleaner use in a smoke-impacted community.

Background: Smoke exposure from wildfires or residential wood burning for heat is a public health problem for many communities. Do-It-Yourself (DIY) portable air cleaners (PACs) are promoted as affordable alternatives to commercial PACs, but evidence of their effect on health outcomes is limited. Objective: Pilot test an evaluation of the effect of DIY PAC usage on self-reported symptoms, and investigate barriers and facilitators of PAC use, among members of a tribal community that routinely experiences elevated concentrations of fine particulate matter (PM2.5) from smoke. Methods: We conducted studies in Fall 2021 ("wildfire study"; N = 10) and Winter 2022 ("wood stove study"; N = 17). Each study included four sequential one-to-two-week phases: 1) initial, 2) DIY PAC usage ≥8 h/day, 3) commercial PAC usage ≥8 h/day, and 4) air sensor with visual display and optional PAC use. We continuously monitored PAC usage and indoor/outdoor PM2.5 concentrations in homes. Concluding each phase, we conducted phone surveys about participants' symptoms, perceptions, and behaviors. We analyzed symptoms associated with PAC usage and conducted an analysis of indoor PM2.5 concentrations as a mediating pathway using mixed effects multivariate linear regression. We categorized perceptions related to PACs into barriers and facilitators of use. Results: No association was observed between PAC usage and symptoms, and the mediation analysis did not indicate that small observed trends were attributable to changes in indoor PM2.5 concentrations. Small sample sizes hindered the ability to draw conclusions regarding the presence or absence of causal associations. DIY PAC usage was low; loud operating noise was a barrier to use. Discussion: This research is novel in studying health effects of DIY PACs during wildfire and wood smoke exposures. Such research is needed to inform public health guidance. Recommendations for future studies on PAC use during smoke exposure include building flexibility of intervention timing into the study design.

Using Geospatial Data and Random Forest To Predict PFAS Contamination in Fish Tissue in the Columbia River Basin, United States.

Decision makers in the Columbia River Basin (CRB) are currently challenged with identifying and characterizing the extent of per- and polyfluoroalkyl substances (PFAS) contamination and human exposure to PFAS. This work aims to develop and pilot a methodology to help decision makers target and prioritize sampling investigations and identify contaminated natural resources. Here we use random forest models to predict ∑PFAS in fish tissue; understanding PFAS levels in fish is particularly important in the CRB because fish can be a major component of tribal and indigenous people diet. Geospatial data, including land cover and distances to known or potential PFAS sources and industries, were leveraged as predictors for modeling. Models were developed and evaluated for Washington state and Oregon using limited available empirical data. Mapped predictions show several areas where detectable concentrations of PFAS in fish tissue are predicted to occur, but prior sampling has not yet confirmed. Variable importance is analyzed to identify potentially important sources of PFAS in fish in this region. The cost-effective methodologies demonstrated here can help address sparsity of existing PFAS occurrence data in environmental media in this and other regions while also giving insights into potentially important drivers and sources of PFAS in fish.

Effects of Controlled Ozone Exposure on Circulating microRNAs and Vascular and Coagulation Biomarkers: A Mediation Analysis.

Exposure to ozone (O3) is associated with adverse respiratory and cardiovascular outcomes. Alterations in circulating microRNAs (miRNAs) may contribute to the adverse vascular effects of O3 exposure through inter-cellular communication resulting in post-transcriptional regulation of messenger RNAs by miRNAs. In this study, we investigated whether O3 exposure induces alterations in circulating miRNAs that can mediate effects on downstream vascular and coagulation biomarkers. Twenty-three healthy male adults were exposed on successive days to filtered air and 300 ppb O3 for 2 h. Circulating miRNA and protein biomarkers were quantified after each exposure session. The data were subjected to mixed-effects model and mediation analyses for the statistical analyses. The results showed that the expression level of multiple circulating miRNAs (e.g., miR-19a-3p, miR-34a-5p) was significantly associated with O3 exposure. Pathway analysis showed that these miRNAs were predictive of changing levels of downstream biomarkers [e.g., D-dimer, C-reactive protein, tumor necrosis factor α (TNFα)]. Mediation analysis showed that miR-19a-3p may be a significant mediator of O3-exposure-induced changes in blood TNFα levels [0.08 (0.01, 0.15), p = 0.02]. In conclusion, this preliminary study showed that O3 exposure of healthy male adults resulted in changes in circulating miRNAs, some of which may mediate vascular effects of O3 exposure.

Urban heat island impacts on heat-related cardiovascular morbidity: A time series analysis of older adults in US metropolitan areas.

Many United States (US) cities are experiencing urban heat islands (UHIs) and climate change-driven temperature increases. Extreme heat increases cardiovascular disease (CVD) risk, yet little is known about how this association varies with UHI intensity (UHII) within and between cities. We aimed to identify the urban populations most at-risk of and burdened by heat-related CVD morbidity in UHI-affected areas compared to unaffected areas. ZIP code-level daily counts of CVD hospitalizations among Medicare enrollees, aged 65-114, were obtained for 120 US metropolitan statistical areas (MSAs) between 2000 and 2017. Mean ambient temperature exposure was estimated by interpolating daily weather station observations. ZIP codes were classified as low and high UHII using the first and fourth quartiles of an existing surface UHII metric, weighted to each have 25% of all CVD hospitalizations. MSA-specific associations between ambient temperature and CVD hospitalization were estimated using quasi-Poisson regression with distributed lag non-linear models and pooled via multivariate meta-analyses. Across the US, extreme heat (MSA-specific 99th percentile, on average 28.6 °C) increased the risk of CVD hospitalization by 1.5% (95% CI: 0.4%, 2.6%), with considerable variation among MSAs. Extreme heat-related CVD hospitalization risk in high UHII areas (2.4% [95% CI: 0.4%, 4.3%]) exceeded that in low UHII areas (1.0% [95% CI: -0.8%, 2.8%]), with upwards of a 10% difference in some MSAs. During the 18-year study period, there were an estimated 37,028 (95% CI: 35,741, 37,988) heat-attributable CVD admissions. High UHII areas accounted for 35% of the total heat-related CVD burden, while low UHII areas accounted for 4%. High UHII disproportionately impacted already heat-vulnerable populations; females, individuals aged 75-114, and those with chronic conditions living in high UHII areas experienced the largest heat-related CVD impacts. Overall, extreme heat increased cardiovascular morbidity risk and burden in older urban populations, with UHIs exacerbating these impacts among those with existing vulnerabilities.

Health Research in the Wake of Disasters: Challenges and Opportunities for Sensor Science.

BACKGROUND: Disaster events adversely affect the health of millions of individuals each year. They create exposure to physical, chemical, biological, and psychosocial hazards while simultaneously exploiting community and individual-level vulnerabilities that allow such exposures to exert harm. Since 2013, the National Institute of Environmental Health Sciences (NIEHS) has led the development of the Disaster Research Response (DR2) program and infrastructure; however, research exploring the nature and effects of disasters on human health is lacking. One reason for this research gap is the challenge of developing and deploying cost-effective sensors for exposure assessment during disaster events. OBJECTIVES: The objective of this commentary is to synergize the consensus findings and recommendations from a panel of experts on sensor science in support of DR2. METHODS: The NIEHS convened the workshop, "Getting Smart about Sensors for Disaster Response Research" on 28 and 29 July 2021 to discuss current gaps and recommendations for moving the field forward. The workshop invited full discussion from multiple viewpoints, with the goal of identifying recommendations and opportunities for further development of this area of research. The panel of experts included leaders in engineering, epidemiology, social and physical sciences, and community engagement, many of whom had firsthand experience with DR2. DISCUSSION: The primary finding of this workshop is that exposure science in support of DR2 is severely lacking. We highlight unique barriers to DR2, such as the need for time-sensitive exposure data, the chaos and logistical challenges that ensue from a disaster event, and the lack of a robust market for sensor technologies in support of environmental health science. We highlight a need for sensor technologies that are more scalable, reliable, and versatile than those currently available to the research community. We also recommend that the environmental health community renew efforts in support of DR2 facilitation, collaboration, and preparedness. https://doi.org/10.1289/EHP12270.

Wildfire smoke exposure and early childhood respiratory health: a study of prescription claims data.

Wildfire smoke is associated with short-term respiratory outcomes including asthma exacerbation in children. As investigations into developmental wildfire smoke exposure on children's longer-term respiratory health are sparse, we investigated associations between developmental wildfire smoke exposure and first use of respiratory medications. Prescription claims from IBM MarketScan Commercial Claims and Encounters database were linked with wildfire smoke plume data from NASA satellites based on Metropolitan Statistical Area (MSA). A retrospective cohort of live infants (2010-2016) born into MSAs in six western states (U.S.A.), having prescription insurance, and whose birthdate was estimable from claims data was constructed (N = 184,703); of these, gestational age was estimated for 113,154 infants. The residential MSA, gestational age, and birthdate were used to estimate average weekly smoke exposure days (smoke-day) for each developmental period: three trimesters, and two sequential 12-week periods post-birth. Medications treating respiratory tract inflammation were classified using active ingredient and mode of administration into three categories:: 'upper respiratory', 'lower respiratory', 'systemic anti-inflammatory'. To evaluate associations between wildfire smoke exposure and medication usage, Cox models associating smoke-days with first observed prescription of each medication category were adjusted for infant sex, birth-season, and birthyear with a random intercept for MSA. Smoke exposure during postnatal periods was associated with earlier first use of upper respiratory medications (1-12 weeks: hazard ratio (HR) = 1.094 per 1-day increase in average weekly smoke-day, 95%CI: (1.005,1.191); 13-24 weeks: HR = 1.108, 95%CI: (1.016,1.209)). Protective associations were observed during gestational windows for both lower respiratory and systemic anti-inflammatory medications; it is possible that these associations may be a consequence of live-birth bias. These findings suggest wildfire smoke exposure during early postnatal developmental periods impact subsequent early life respiratory health.

Risk of systemic fungal infections after exposure to wildfires: a population-based, retrospective study in California.

BACKGROUND: Large-scale wildfires in California, USA, are increasing in both size and frequency, with substantial health consequences. The capacity for wildfire smoke to displace microbes and cause clinically significant fungal infections is poorly understood. We aimed to determine whether exposure to wildfire smoke was associated with an increased risk of hospital admissions for systemic fungal infections. METHODS: In this population-based, retrospective study, we used hospital administrative data from 22 hospitals in California, USA, to analyse the association between wildfire smoke exposure and monthly hospital admissions for aspergillosis and coccidioidomycosis. We included hospitals that were members of the Vizient Clinical Data Base or Resource Manager during the study and excluded those that did not have complete reporting into Vizient during the study period. Smoke exposure was estimated using satellite-imaged smoke plumes in the hospital county. Incident rate ratios were calculated for all infection types 1 month and 3 months after smoke exposure. FINDINGS: Between Oct 1, 2014, and May 31, 2018, there were a median of 1638 annual admissions per hospital in the study sample. Individual patient demographics were not collected. We did not observe an association between smoke exposure and rate of hospital admission for aspergillosis. However, hospital admission for coccidioidomycosis increased by 20% (95% CI 5-38) in the month following any smoke exposure. Hospital admission increased by 2% (0-4) for every day that there had been smoke exposure in the previous month, after adjustment for temperature and temporal trend. Similar results were obtained with smoke exposure data from the 3 months before admission. INTERPRETATION: In the months following wildfire smoke exposure, California hospitals saw increased coccidioidomycosis infections. Given the projected increase in California wildfires and their expansion in endemic territories of soil-dwelling fungi, the ability for wildfire smoke to carry microbes and cause human disease warrants further research. FUNDING: None.

Long-term exposure to ambient O3 and PM2.5 is associated with reduced cognitive performance in young adults: A retrospective longitudinal repeated measures study in adults aged 18-90 years.

A growing body of evidence indicates that exposure to air pollution affects cognitive performance; however, few studies have assessed this in the context of repeated measures within a large group of individuals or in a population with a large age range. In this study, we evaluated the associations between long-term exposure to fine particulate matter (PM2.5) and ozone (O3) in large cohort of adults aged 18-90 years. The study cohort included 29,091 Lumosity users in the contiguous US who completed 20 repetitions of the Lost in Migration game between 2017 and 2018. Game scores reflect the ability to filter information and avoid distracting information. Long-term air pollution data included ambient PM2.5 and O3 averaged for the 365-day period before each gameplay date. Generalized linear models were used to examine the associations between long-term PM2.5 and O3 and game score percentile. Co-pollutant models were adjusted for meteorology, time trend, age, gender, device, education, local socioeconomic factors, and urbanicity. Results represent the change in attention game score percentile per 1 µg/m3 increase in PM2.5 or 0.01 ppm increase in O3. In the entire cohort, a -0.10 (95% CI: -0.16, -0.04) change in score percentile was associated with PM2.5, while no significant association was observed with O3. Modification of these associations by age was observed for both PM2.5 and O3, with stronger associations observed in younger users. In users aged 18-29, a -0.25 (-0.45, -0.05) change in score percentile was associated with PM2.5, while no associations were observed in other age groups. With O3, there was a -2.92 (-4.63, -1.19) and -2.81 (-4.29, -1.25) change in score percentile for users aged 18-29 and 30-39, respectively. We observed that elevated long-term PM2.5 and O3 were associated with decreased focus scores in young adults, but follow-up research is necessary to further illuminate these associations.

Associations of Air Pollution and Serum Biomarker Abnormalities in Individuals with Hemodialysis-Dependent Kidney Failure.

BACKGROUND: Ambient particles with a median aerodynamic diameter of <2.5 µm (PM2.5) is a ubiquitous air pollutant with established adverse health consequences. While postulated to promote a systemic inflammatory response, limited studies have demonstrated changes in serum biomarkers related to PM2.5 exposure. We aim to examine associations between short-term PM2.5 exposure and commonly measured biomarkers known to be affected by inflammation among patients receiving maintenance in-center hemodialysis. METHODS: We conducted a retrospective open cohort study from January 1, 2008, to December 31, 2014. Adult hemodialysis patients were identified from the United States Renal Data System and linked at the patient level to laboratory data from a large dialysis organization. Daily ambient PM2.5 was estimated on a 1-km grid and assigned to cohort patients based on the ZIP codes of dialysis clinics. Serum albumin, serum ferritin, transferrin saturation (TSAT), and serum hemoglobin were ascertained from the dialysis provider organization database. Mixed-effect models were used to assess the changes in biomarker levels associated with PM2.5 exposure. RESULTS: The final cohort included 173,697 hemodialysis patients. Overall, the daily ZIP-level ambient PM2.5 averages were 8.4-8.5 µg/m3. A 10-µg/m3 increase in same-day ambient PM2.5 exposure was associated with higher relative risks of lower albumin (relative risk [RR], 1.01; 95% confidence interval [95% CI], 1.01 to 1.02) and lower hemoglobin (RR, 1.02; 95% CI, 1.01 to 1.03). Associations of same-day ambient PM2.5 exposure and higher ferritin and lower TSAT did not reach statistical significance. CONCLUSIONS: Short-term PM2.5 exposure was associated with lower serum hemoglobin and albumin among patients receiving in-center hemodialysis. These findings lend support to the role of inflammation in PM2.5 exposure-outcome associations.

Responses to Wildfire and Prescribed Fire Smoke: A Survey of a Medically Vulnerable Adult Population in the Wildland-Urban Interface, Mariposa County, California.

California plans to substantially increase the use of prescribed fire to reduce risk of catastrophic wildfires. Although for a beneficial purpose, prescribed fire smoke may still pose a health concern, especially among sensitive populations. We sought to understand community health experience, adaptive capacity, and attitudes regarding wildland and prescribed fire smoke to inform public health guidance. We conducted a cross-sectional survey of medically vulnerable persons in a rural, high fire risk county (N = 106, 76% > 65 years) regarding wildfire and prescribed smoke health effects; health protective actions; information needs; and support for fire management policies. Qualitative comments were reviewed for context and emerging themes. More than half (58%) of participants reported health impacts from wildfire smoke; 26% experienced impacts from prescribed fire smoke. Participants expressed strong support for prescribed fire, although also concerns about safety and smoke. Respondents reported taking actions to reduce smoke exposure (average 5 actions taken per person), but many (47%) lacked confidence that they could successfully protect their health. Persons who were satisfied with the information received tended to be more confident in their ability to protect their health compared to those who were not satisfied (61% vs. 35%). More information was desired on many topics, including notifications about prescribed fire, health protection and exposure reduction. As California expands use of prescribed fire, the need for effective health protective communication regarding smoke is increasingly vital. We recommend seeking solutions that strengthen community resilience and address equity for vulnerable populations.

Feasibility and acceptability of home monitoring with portable spirometry in young adults with asthma.

OBJECTIVE: Self-monitoring asthma control is a key component of asthma management. Few studies have reported usability and acceptability of portable spirometry among young adults with asthma. Portable spirometry offers a practical solution to monitoring airway narrowing at home. The purpose of this paper was to determine if self-administered spirometry is feasible and acceptable in young adults with asthma and whether regular monitoring resulted in improved airway function as measured by forced expiratory volume in one second (FEV1). METHODS: Sixty-seven young adults (18-26 years) with self-reported asthma participated in a clinical trial during wildfire season which measured FEV1 as an outcome measure. Data was collected at baseline, week 4, and week 8 using a portable spirometer linked to a smartphone application. A subset of intervention participants completed spirometry twice daily. Acceptability of self-administered spirometry was evaluated after the trial among participants that volunteered to submit a survey and be interviewed. RESULTS: At baseline, all 67 participants (100.0%) completed their scheduled spirometry readings which declined to 94.0% (n = 63) at week 4 and 86.6% (n = 58) at week 8. Daily readings were completed 83.2% of the time in the mornings and 84.3% of the time in the evenings. Mean FEV1 values were lower than predicted values, but above the lower limit of expected. FEV1 remained steady throughout the study period. Over two-thirds of participants used the notes feature in the application and described symptoms, asthma triggers, mitigating actions and test-taking issues. CONCLUSIONS: Young adults in our sample were highly compliant with regular, self-administered spirometry.

Wildfires and the Changing Landscape of Air Pollution-related Health Burden in California.

Rationale: Wildfires are a growing source of pollution including particulate matter ⩽2.5 µm in aerodynamic diameter (PM2.5), but associated trends in health burden are not well characterized. Objectives: We investigated trends and disparities in PM2.5-related cardiorespiratory health burden (asthma, chronic obstructive pulmonary disease, and all-cause respiratory and cardiovascular emergency department [ED] visits and hospital admissions) for all days and wildfire smoke-affected days across California from 2008 to 2016. Methods: Using residential Zone Improvement Plan code and daily PM2.5 exposures, we estimated overall and subgroup-specific (age, gender, race and ethnicity) associations with cardiorespiratory outcomes. Health burden trends and disparities were evaluated on the basis of relative risk, attributable number, and attributable fraction by demographic and geographic factors and over time. Measurements and Main Results: PM2.5-attributed burden steadily decreased, whereas the fraction attributed to wildfire smoke varied by fire season intensity, constituting up to 15% of the annual PM2.5-burden. The highest relative risk and PM2.5-attributed burden (92 per 100,000 people) was observed for respiratory ED visits, accounting for 2.2% of the respiratory annual burden. Disparities in overall morbidity in the oldest age, Black, and "other" race groups were also reflected in PM2.5-attributed burden, whereas Asian populations had the highest risk rate in respiratory outcomes and thus the largest fraction of the total burden attributed to the exposure. In contrast, high wildfire PM2.5-attributed burden rates in rural, central, and northern California populations occurred because of differential exposure. Conclusions: In California, wildfires' impact on air quality offset the public health gains achieved through reductions in nonsmoke PM2.5. Disproportionate effects could be attributed to differences in subpopulation susceptibility, relative risk, and differential exposure.

Improvement in Fitted Filtration Efficiency of N95 Respirators With Escalating Instruction of the Wearer.

Introduction: Fitted filtration performance of an N95 respirator may benefit from differing levels of instructions. Methods: Using a modified Occupational Safety and Health Administration fit test protocol, we measured fitted filtration efficiency for an N95 respirator in 21 screened, healthy participants given 4 levels of escalating instruction: (1) uninstructed (baseline), (2) written/pictorial manufacturer instructions, (3) step-by-step video demonstration, and (4) staff instruction (visual inspection of respirator fit and verbal suggestions to adjust when applicable). Results: Baseline fitted filtration efficiency was not significantly different between participants with or without previous experience of N95 use. Clear improvements in fitted filtration efficiency were observed progressing from baseline (average=86.1%) to manufacturer paper instructions (93.3%), video instructions (97.5%), and post staff intervention (98.3%). Baseline fitted filtration efficiency values were significantly lower than those after video instruction (p<0.037) and staff intervention (p<0.033) sessions. Conclusions: Beyond uninstructed wear or provision of manufacturer instructions, efforts to train and instruct users in proper respirator fit principles with visual feedback are likely to yield benefits to public health outcomes in reducing respiratory exposure during air quality emergencies such as airborne viral outbreaks and wildland fires.

Estimating intervention effects on infectious disease control: The effect of community mobility reduction on Coronavirus spread.

Understanding the effects of interventions, such as restrictions on community and large group gatherings, is critical to controlling the spread of COVID-19. Susceptible-Infectious-Recovered (SIR) models are traditionally used to forecast the infection rates but do not provide insights into the causal effects of interventions. We propose a spatiotemporal model that estimates the causal effect of changes in community mobility (intervention) on infection rates. Using an approximation to the SIR model and incorporating spatiotemporal dependence, the proposed model estimates a direct and indirect (spillover) effect of intervention. Under an interference and treatment ignorability assumption, this model is able to estimate causal intervention effects, and additionally allows for spatial interference between locations. Reductions in community mobility were measured by cell phone movement data. The results suggest that the reductions in mobility decrease Coronavirus cases 4 to 7 weeks after the intervention.

Can disposable masks be worn more than once?

Disposable facemasks are a primary tool to prevent the transmission of SARS-COV-2 during the COVID-19 pandemic. However, plastic waste generated from their disposal represents a significant environmental problem that can be reduced by maximizing the service life of disposable masks. We evaluated the effect of repeated wearing on the fitted filtration efficiency (FFE) of N95, KF94, KN95, and procedure/surgical masks. The FFEs of masks were compared following extended wearing with and without washing. Results reveal that most disposable facemasks can retain a high level of their baseline FFE after extended wearing, even after 40 h of wearing. Laundering disposable masks degraded FFE in some instances. We conclude that the durability of disposable facemask performance is considerably longer than their intended single use indication, suggesting that reusing disposable masks is a safe means of reducing plastic waste in the environment.

Fish oil blunts lung function decrements induced by acute exposure to ozone in young healthy adults: A randomized trial.

BACKGROUND: Over one-third of the U.S. population is exposed to unsafe levels of ozone (O3). Dietary supplementation with fish oil (FO) or olive oil (OO) has shown protection against other air pollutants. This study evaluates potential cardiopulmonary benefits of FO or OO supplementation against acute O3 exposure in young healthy adults. METHODS: Forty-three participants (26 ± 4 years old; 47% female) were randomized to receive 3 g/day of FO, 3 g/day OO, or no supplementation (CTL) for 4 weeks prior to undergoing 2-hour exposures to filtered air and 300 ppb O3 with intermittent exercise on two consecutive days. Outcome measurements included spirometry, sputum neutrophil percentage, blood markers of inflammation, tissue injury and coagulation, vascular function, and heart rate variability. The effects of dietary supplementation and O3 on these outcomes were evaluated with linear mixed-effect models. RESULTS: Compared with filtered air, O3 exposure decreased FVC, FEV1, and FEV1/FVC immediately post exposure regardless of supplementation status. Relative to that in the CTL group, the lung function response to O3 exposure in the FO group was blunted, as evidenced by O3-induced decreases in FEV1 (Normalized CTL -0.40 ± 0.34 L, Normalized FO -0.21 ± 0.27 L) and FEV1/FVC (Normalized CTL -4.67 ± 5.0 %, Normalized FO -1.4 ± 3.18 %) values that were on average 48% and 70% smaller, respectively. Inflammatory responses measured in the sputum immediately post O3 exposure were not different among the three supplementation groups. Systolic blood pressure elevations 20-h post O3 exposure were blunted by OO supplementation. CONCLUSION: FO supplementation appears to offer protective effects against lung function decrements caused by acute O3 exposure in healthy adults.

Short-Term Exposure to Wildfire Smoke and PM2.5 and Cognitive Performance in a Brain-Training Game: A Longitudinal Study of U.S. Adults.

BACKGROUND: There is increasing evidence that long-term exposure to fine particulate matter [PM ≤2.5µm in aerodynamic diameter (PM2.5)] may adversely impact cognitive performance. Wildfire smoke is one of the biggest sources of PM2.5 and concentrations are likely to increase under climate change. However, little is known about how short-term exposure impacts cognitive function. OBJECTIVES: We aimed to evaluate the associations between daily and subdaily (hourly) PM2.5 and wildfire smoke exposure and cognitive performance in adults. METHODS: Scores from 20 plays of an attention-oriented brain-training game were obtained for 10,228 adults in the United States (U.S.). We estimated daily and hourly PM2.5 exposure through a data fusion of observations from multiple monitoring networks. Daily smoke exposure in the western U.S. was obtained from satellite-derived estimates of smoke plume density. We used a longitudinal repeated measures design with linear mixed effects models to test for associations between short-term exposure and attention score. Results were also stratified by age, gender, user behavior, and region. RESULTS: Daily and subdaily PM2.5 were negatively associated with attention score. A 10 µg/m3 increase in PM2.5 in the 3 h prior to gameplay was associated with a 21.0 [95% confidence interval (CI): 3.3, 38.7]-point decrease in score. PM2.5 exposure over 20 plays accounted for an estimated average 3.7% (95% CI: 0.7%, 6.7%) reduction in final score. Associations were more pronounced in the wildfire-impacted western U.S. Medium and heavy smoke density were also negatively associated with score. Heavy smoke density the day prior to gameplay was associated with a 117.0 (95% CI: 1.7, 232.3)-point decrease in score relative to no smoke. Although differences between subgroups were not statistically significant, associations were most pronounced for younger (18-29 y), older (≥70y), habitual, and male users. DISCUSSION: Our results indicate that PM2.5 and wildfire smoke were associated with reduced attention in adults within hours and days of exposure, but further research is needed to elucidate these relationships. https://doi.org/10.1289/EHP10498.