Stacey M. Benson

A case-crossover analysis of the impact of PM2.5 on cardiovascular disease hospitalizations for selected CDC tracking states

BACKGROUND Information is currently being collected by the CDC Environmental Public Health Tracking (EPHT) network on hospitalizations due to Acute Myocardial Infarction (AMI) and there is interest by CDC in exploring the relationship between fine particulate matter (PM2.5) and other cardiovascular (CVD) outcomes in the context of the EPHT program. The goal of this study was to assess the short term effects of daily PM(2.5) air pollution levels on hospitalizations for CVD for seven states within the CDC EPHT network (Florida, Massachusetts, New Hampshire, New Jersey, New Mexico, New York, and Washington). METHODS Hospitalization data was obtained for 2001-2008 admissions for circulatory disease (primary discharge diagnosis of ICD-9 codes 390-459) from data stewards in those states and included admission date, age, gender, and zip code of residence. We used CMAQ-derived predicted daily PM2.5 data as estimated by EPA at the centroid of each Census Bureau Zip Code Tabulation Area (ZCTA) and linked to zip code of patient residence. A time-stratified case-crossover study design with conditional logistic regression was used to evaluate the short-term association of PM2.5 on risk of non-elective hospitalizations for CVD. Specifically, we considered all circulatory disease, ischemic heart disease, acute myocardial infarction, heart failure, cardiac arrhythmia, cerebrovascular disease and peripheral vascular disease endpoints. RESULTS Data were obtained on over 7,500,000 hospitalizations for this time period. Mean annual PM2.5 exposure levels were lowest for New Mexico and Washington (6.5 μg/m3 PM2.5 and 8.4 μg/m3 PM2.5). New Jersey, New York and Massachusetts exhibited the highest annual averages for PM2.5, (12.8 μg/m3, 11.1 μg/m3 and 10.8 μg/m3), respectively. The Northeast states (Massachusetts, New Jersey, New Hampshire and New York) exhibited significant effects of PM2.5 during the cooler months across most disease categories after adjustment for ozone and maximum apparent temperature. Ischemic heart disease risk per 10 μg/m3 increase in PM2.5 varied from 1.02 to 1.05 for the cooler months. The largest lag effect was noted on lag days 0 and 1. New Mexico and Washington exhibited no cool or warm month significant effects. Although Florida showed no cooler month effects, significant increases were noted in odds ratios for the warm weather months for all outcomes except peripheral vascular disease. This study is one of the first large scale applications of linkage of hospitalization data by state with national US EPA statistically modeled air pollution data. The results demonstrate that state-wide, there are multiple cardiovascular outcomes in addition to AMI which may be impacted by particulate air pollution.

Trends in Acute Myocardial Infarction Hospitalization Rates for US States in the CDC Tracking Network

Objectives We examined temporal trends, spatial variation, and gender differences in rates of hospitalization due to acute myocardial infarction. Methods We used data from the Centers for Disease Control National Environmental Public Health Tracking Network to evaluate temporal trends, geographic variation, and gender differences in 20 Environmental Public Health Tracking Network states from 2000 to 2008. A longitudinal linear mixed effects model was fitted to the acute myocardial infarction hospitalization rates for the states and counties within each state to examine the overall temporal trend. Results There was a significant overall decrease in age-adjusted acute myocardial infarction hospitalization rates between 2000 and 2008, with most states showing over a 20% decline during the period. The ratio of male/female rates for acute myocardial infarction hospitalization rates remained relatively consistent over time, approximately two-fold higher in men compared to women. A large geographic variability was found for age-adjusted acute myocardial infarction hospitalization rates, with the highest rates found in the Northeastern states. Results of two ecological analyses revealed that the NE region remained significantly associated with increased AMI hospitalization rates after adjustment for socio-demographic factors. Conclusions This investigation is one of the first to explore geographic differences in AMI age adjusted hospital rates in individuals 35+ years of age for 2000–2008. We showed a decreasing trend in AMI hospitalization rates in men and women. A large geographic variability in rates was found with particularly higher rates in the New England/Mid-Atlantic region of the US and lower rates in the mountain and Pacific states of the tracking network. It appeared that over time this disparity in rates became less notable.

Non-occupational exposure to asbestos and risk of pleural mesothelioma: review and meta-analysis

Objective To conduct an updated literature review and meta-analysis of studies of pleural malignant mesothelioma (PMM) risk among persons exposed to asbestos non-occupationally (household and neighbourhood). Methods We performed a literature search for articles available in the National Center for Biotechnology Information’s PubMed database published between 1967 and 2016. Meta-analyses were conducted to calculate pooled PMM risk estimates, stratifying for household or neighbourhood exposure to asbestos and/or predominant asbestos fibre type (chrysotile, amphibole or mixed). Results Eighteen studies in 12 countries comprising 665 cases met the meta-analysis inclusion criteria. We identified 13 estimates of PMM risk from neighbourhood exposures, 10 from household and one from mixed exposure, and combined the estimates using random-effects models. The overall meta-relative risk (meta-RR) was 5.9 (95% CI 4.4 to 8.7). The meta-RRs for household and neighbourhood exposures were 5.4 (95% CI 2.6 to 11.2) and 6.9 (95% CI 4.2 to 11.4), respectively. We observed trends in risk in relation to fibre type for both household and neighbourhood studies. For chrysotile, mixed and amphibole fibres, respectively, meta-RRs for neighbourhood studies were 3.8 (95% CI 0.4 to 38.4), 8.4 (95% CI 4.7 to 14.9) and 21.1 (95% CI 5.3 to 84.5) and meta-RRs for household studies were 4.0 (95% CI 0.8 to 18.8), 5.3 (95% CI 1.9 to 15.0) and 21.1 (95% CI 2.8 to 156.0). Conclusions PMM risks from non-occupational asbestos exposure are consistent with the fibre-type potency response observed in occupational settings. By relating our findings to knowledge of exposure-response relationships in occupational settings, we can better evaluate PMM risks in communities with ambient asbestos exposures from industrial or other sources.

Analysis of Forces Generated by N95 Filtering Facepiece Respirator Tethering Devices: A Pilot Study

The restorative forces of elasticized tethering devices on N95 filtering facepiece respirators (N95 FFR), that occur in response to the application of a load (applied force) during donning, create the requisite pressure to effectively seal the respirator against the face and prevent excessive inward migration of harmful elements. Many workers don and doff the same N95 FFR multiple times in the course of a single workday, yet little is known regarding the possible degradation of these restorative loads and, by implication, protection with multiple donnings. This laboratory pilot study evaluated the degradation in loads of tethering devices of three models of N95 FFRs subjected to the strain of five wear periods of 15 min interspersed with 15-min periods without wear. Data indicate that there were load degradations at each donning that differed significantly with the FFR model (p = <0.001), the greatest of which occurred with the first donning. The N95 FFR model with the lowest restorative loads was able to pass fit testing in a previous study, indicating that lower loads, perhaps coupled with FFR model-specific features, are sufficient to provide an adequate face/FFR interface seal. Tethering devices are importantly related to issues of comfort and protection afforded by N95 FFR and additional research is warranted.

Cosmetic talc as a risk factor for pleural mesothelioma: a weight of evidence evaluation of the epidemiology

Abstract Objective: Due to some historical (and inaccurate) reports that asbestos might be present in some cosmetic talc products, questions are occasionally raised regarding the potential pleural mesothelioma risks associated with cosmetic talc products. Our objective was to determine the incidence of pleural mesothelioma of individuals exposed to cosmetic talc. Materials and methods: We conducted a systematic review of the epidemiological literature for cosmetic talc miners and millers and found three occupational cohort studies that evaluated pleural mesothelioma incidence in workers in Italy, Norway, France, and Austria. We conducted a second literature review to evaluate the incidence and mortality of pleural mesothelioma among patients who received talc pleurodesis treatments before 1965 and found retrospective clinical studies including over 300 patients with follow-up ranging from 14 to 40 years. Results: There were no mesotheliomas reported in any of the cosmetic talc miner and miller cohorts. A pooled analysis of data from the cohort mortality studies indicated that four mesothelioma deaths would have been expected from the 90,022 person-years of observation, and this was associated with 84% and 67% statistical power to observe a 3-fold or 2.5-fold increase in pleural mesothelioma mortality, respectively. None of the patients who received talc pleurodesis treatments developed mesothelioma. Conclusion: We conclude that there is no epidemiological evidence to support the hypothesis that exposure to cosmetic talc is associated with the development of pleural mesothelioma.

Environmental lead and childhood blood lead levels in US children: NHANES, 1999–2006

ABSTRACT Although blood lead levels in the United States have fallen dramatically since 1980, there remain subgroups of children with high blood lead levels. We assessed the relationship between environmental lead sources and blood lead levels in children ages 1 to 5 years from the National Health and Nutrition Examination Survey (NHANES), 1999–2006. Modeled ambient air lead levels and industrial lead releases at the census-tract level were assigned to each childs residence with adjustment for confounding factors. Of 3,223 children, 272 (8.4%) had blood lead levels ≥ 5 ug/dL. Industrial releases (2,252 vs 1,696 lbs/mi2) and ambient air lead levels (2.28 vs 1.75 ng/m3) were greater in exposed versus unexposed children. For every 10,000 lb/mi2 increase in inverse distance squared weighted exposure, there was a 1.13% increase (95% CI: 0.45%, 1.81%) in blood lead (p = .001).

Response to: ‘Pleural mesothelioma and occupational and non-occupational asbestos exposure: a case-control study with quantitative risk assessment’ by Ferrante et al

We read with interest the 2016 paper by Ferrante et al ,1 who evaluated the relationship between occupational and non-occupational asbestos exposures and the risk of pleural malignant mesothelioma (PMM) among workers and residents in the Casale Monferrato area of Italy, the site of a former asbestos cement factory. We also read the subsequent letter from Boffetta,2 who identified many problematic methodological issues with the Ferrante et al 1 study, most notably: limited detail regarding exposure estimation methods, lack of reproducibility, inconsistencies in findings and potential study biases. In a response, Ferrante et al 3 challenged but did not resolve all issues raised by Boffetta.2 For example, Ferrante et al 3 countered Boffettas2 criticism about limited exposure estimation detail by citing a paper not referenced in their original publication.1 Furthermore, …

Revisiting Nonresidential Environmental Exposures and Childhood Lead Poisoning in the US: Findings from Kansas, 2000–2005

Although blood lead levels (BLLs) in US children have dramatically declined over the past 40 years, there remain pockets of children living in areas with elevated BLLs. While some increases (≥10 μg/dL) may be associated with legacy lead paint, ambient air lead may be contributing to the problem. A deidentified dataset of information on over 60,000 Kansas children under 3 years of age who were tested for BLL was provided through the Kansas Environmental Public Health Tracking Network for the period 2000–2005. Using ArcGIS, we calculated distance (in miles) from a lead-emitting industry referred to as a toxic release inventory (TRI) site. The USEPA TRI database tracks the management of certain toxic chemicals that may pose a threat to human health. US facilities in different industry sectors must report annually amount of substances like lead into the environment including their exact location. Distance from a TRI site was inversely related to BLL after controlling for area-level poverty and pre-1950 housing. The results of our evaluation indicate there is a significant relationship between proximity to lead industry and childhood BLLs. Proximity to sources of lead emissions should be evaluated as a possible factor when identifying children for targeted BLL testing.

Can 8-hydroxy-2′-deoxyguanosine be used to assess oxidative stress caused by particulate matter air pollution in the general population?

ObjectivesAssess the association between 8-hydroxy-2′-deoxyguanosine (8OHdG) levels and particulate matter air pollution in non-occupational exposure groups from peer-reviewed literature.MethodsOvid Medline and PubMed were used to search for all peer-reviewed articles published between 1946 and May 2013. Keywords included particulate matter, air pollution, deoxyguanosine, 8-hydroxy-2′-deoxyguanosine, and known abbreviations. Seven English, non-occupational exposure, human subject studies were evaluated.ResultsOf the two studies involving children one found significant positive associations between exposure to particulate matter air pollution and 8OHdG. Investigations into non-occupationally exposed adults were mixed. The lone double-blind crossover study found no relationship between diesel exhaust exposure and 8OHdG. Two out of three panel studies and one cohort study found significant associations between 8OHdG and classes of particles and for various lags.ConclusionsAnalyses accounting for particle composition and lags between exposure and physiological responses had the strongest significant associations. Results are not conclusive due to the inconsistency in study designs, small sample sizes, and differences in exposure assessment techniques. Consistent methodology with representative populations including women and other non-occupationally exposed groups are recommended.

Response to: ‘Reanalysis of non-occupational exposure to asbestos and the risk of pleural mesothelioma’ by Finkelstein

We reviewed the letter submitted by Finkelstein1 regarding our paper evaluating the risk of pleural mesothelioma from non-occupational asbestos exposure.2 Finkelstein indicated that, in addition to two Canadian studies in our analysis,3 4 a third unpublished report was produced in 2004 by Quebec Public Health.5 It is unclear if Finkelstein is suggesting that the Quebec report is an update to both Camus3 and McDonald,4 but it should be noted that although the study populations were similar, case ascertainment was different. Finkelstein1 cited that the historical progression of case ascertainment for pleural mesothelioma among women with neighbourhood exposure in the Quebec mining regions was 0 cases in 1980,4 7 cases in 19983 and 17 cases in 2004.5 However, in 2004, Quebec Public Health only reported a total of 10 cases of pleural mesothelioma among women …