Meta-Analysis of Heterogeneity in the Effects of Wildfire Smoke Exposure on Respiratory Health in North America.

Epidemiological studies consistently show an association between wildfire-related smoke exposure and adverse respiratory health. We conducted a systematic review of evidence in published literature pertaining to heterogeneity of respiratory effects from this exposure in North America. We calculated the within-study ratio of relative risks (RRR) and 95% confidence intervals (CI) to examine heterogeneity of effect by population subgroup, and then summarized the RRRs using meta-analysis. We found evidence of a greater effect of wildfire smoke on respiratory health among females relative to males for asthma (RRR: 1.035, 95% CI: 1.013, 1.057) and chronic obstructive pulmonary disease (RRR: 1.018, 95% CI: 1.003, 1.032). There was evidence of a lower relative risk for all respiratory outcomes among youth compared to adults (RRR: 0.976, 95% CI: 0.963, 0.989). We also found wildfire smoke effects stratified by income, race, education, health behaviors, access to care, housing occupancy, geographic region, and urban/rural status. However, data were insufficient to quantitatively evaluate effect modification by these characteristics. While we found evidence that certain demographic subgroups of the population are more susceptible to respiratory health outcomes from wildfire smoke, it is unclear whether this information can be used to inform policy aimed to reduce health impact of wildfires.

South Philadelphia passive sampler and sensor study.

UNLABELLED: From June 2013 to March 2015, in total 41 passive sampler deployments of 2 wk duration each were conducted at 17 sites in South Philadelphia, PA, with results for benzene discussed here. Complementary time-resolved measurements with lower cost prototype fenceline sensors and an open-path ultraviolet differential optical absorption spectrometer were also conducted. Minimum passive sampler benzene concentrations for each sampling period ranged from 0.08 ppbv to 0.65 ppbv, with a mean of 0.25 ppbv, and were negatively correlated with ambient temperature (-0.01 ppbv/°C, R(2) = 0.68). Co-deployed duplicate passive sampler pairs (N = 609) demonstrated good precision with an average and maximum percent difference of 1.5% and 34%, respectively. A group of passive samplers located within 50 m of a refinery fenceline had a study mean benzene concentration of 1.22 ppbv, whereas a group of samplers located in communities >1 km distant from facilities had a mean of 0.29 ppbv. The difference in the means of these groups was statistically significant at the 95% confidence level (p < 0.001). A decreasing gradient in benzene concentrations moving away from the facilities was observed, as was a significant period-to-period variation. The highest recorded 2-wk average benzene concentration for the fenceline group was 3.11 ppbv. During this period, time-resolved data from the prototype sensors and the open-path spectrometer detected a benzene signal from the west on one day in particular, with the highest 5-min path-averaged benzene concentration measured at 24 ppbv. IMPLICATIONS: Using a variation of EPA's passive sampler refinery fenceline monitoring method, coupled with time-resolved measurements, a multiyear study in South Philadelphia informed benzene concentrations near facilities and in communities. The combination of measurement strategies can assist facilities in identification and mitigation of emissions from fugitive sources and improve information on air quality complex air sheds.

South Philadelphia passive sampler and sensor study.

From June 2013 to March 2015, in total 41 passive sampler deployments of 2 wk duration each were conducted at 17 sites in South Philadelphia, PA, with results for benzene discussed here. Complementary time-resolved measurements with lower cost prototype fenceline sensors and an open-path ultraviolet differential optical absorption spectrometer were also conducted. Minimum passive sampler benzene concentrations for each sampling period ranged from 0.08 ppbv to 0.65 ppbv, with a mean of 0.25 ppbv, and were negatively correlated with ambient temperature (-0.01 ppbv/°C, R2 = 0.68). Co-deployed duplicate passive sampler pairs (N = 609) demonstrated good precision with an average and maximum percent difference of 1.5% and 34%, respectively. A group of passive samplers located within 50 m of a refinery fenceline had a study mean benzene concentration of 1.22 ppbv, whereas a group of samplers located in communities >1 km distant from facilities had a mean of 0.29 ppbv. The difference in the means of these groups was statistically significant at the 95% confidence level (p < 0.001). A decreasing gradient in benzene concentrations moving away from the facilities was observed, as was a significant period-to-period variation. The highest recorded 2-wk average benzene concentration for the fenceline group was 3.11 ppbv. During this period, time-resolved data from the prototype sensors and the open-path spectrometer detected a benzene signal from the west on one day in particular, with the highest 5-min path-averaged benzene concentration measured at 24 ppbv. IMPLICATIONS: Using a variation of EPA's passive sampler refinery fenceline monitoring method, coupled with time-resolved measurements, a multiyear study in South Philadelphia informed benzene concentrations near facilities and in communities. The combination of measurement strategies can assist facilities in identification and mitigation of emissions from fugitive sources and improve information on air quality complex air sheds.

Working environment and myeloproliferative neoplasm: A population-based case-control study following a cluster investigation.

BACKGROUND: Occupational exposures, including those to polycyclic aromatic hydrocarbons (PAH), are suspected risk factors for myeloproliferative neoplasms (MPN). METHODS: We investigated occupational exposures and MPN risk (54 cases and 472 controls) in a population-based case-control study in three rural Pennsylvania counties. Occupational histories, coded to SIC/SOC 1980, were linked to a previously created PAH job-exposure matrix. Odds ratios for industry (17 categories), occupation (26 categories), and PAH exposure were adjusted using logistic regression. RESULTS: No industries or occupations were strongly or consistently associated with increased MPN risk. Analysis of employment duration found that being employed for 5 or more years in transportation, communications, and other public utilities was associated with MPN risk. There was no indication of an association with cumulative PAH exposure. CONCLUSIONS: These few associations did not appear to have a common exposure. This exploratory study does not support the hypothesis that occupational exposure, including PAH, are strong risk factors for MPNs.

The role of genotypes that modify the toxicity of chemical mutagens in the risk for myeloproliferative neoplasms.

BACKGROUND: The etiology of myeloproliferative neoplasms (MPN) (polycythemia vera; essential thrombocythemia; primary myelofibrosis) is unknown, however they are associated with a somatic mutation--JAK2 V617F--suggesting a potential role for environmental mutagens. METHODS: We conducted a population-based case-control study in three rural Pennsylvania counties of persons born 1921-1968 and residing in the area between 2000-2008. Twenty seven MPN cases and 292 controls were recruited through random digit dialing. Subjects were genotyped and odds ratios estimated for a select set of polymorphisms in environmentally sensitive genes that might implicate specific environmental mutagens if found to be associated with a disease. RESULTS: The presence of NAT2 slow acetylator genotype, and CYP1A2, GSTA1, and GSTM3 variants were associated with an average 3-5 fold increased risk. CONCLUSIONS: Exposures, such as to aromatic compounds, whose toxicity is modified by genotypes associated with outcome in our analysis may play a role in the environmental etiology of MPNs.

Place-based stressors associated with industry and air pollution.

Exposure to air pollution and its sources is increasingly viewed as a psychosocial stress, however its nature is not understood. This article explores the role of the concept of place on risk perception and community stress within data collected from eight focus groups in Philadelphia, USA. Discussions focused on air pollution, a nearby oil refinery, health, and a proposal for air monitoring. We present a framework of place-based elements of risk perception that includes place identity, stigma and social control. Our findings indicate that air pollution contributes to physical and psychosocial conditions that act as community-level social stressors. Findings also suggest that programs which seek to change behaviors and gather or spread information on issues such as pollution and other environmental concerns will be challenged unless they directly address: (1) the public׳s identification with a place or industry, (2) immediate environmental stressors such as abandonment, waste and odors, and (3) public perceptions of lack of social control and fear of displacement.

A multidisciplinary investigation of a polycythemia vera cancer cluster of unknown origin.

Cancer cluster investigations rarely receive significant public health resource allocations due to numerous inherent challenges and the limited success of past efforts. In 2008, a cluster of polycythemia vera, a rare blood cancer with unknown etiology, was identified in northeast Pennsylvania. A multidisciplinary group of federal and state agencies, academic institutions, and local healthcare providers subsequently developed a multifaceted research portfolio designed to better understand the cause of the cluster. This research agenda represents a unique and important opportunity to demonstrate that cancer cluster investigations can produce desirable public health and scientific outcomes when necessary resources are available.