Cardio-respiratory outcomes associated with exposure to wildfire smoke are modified by measures of community health

Abstract

BackgroundCharacterizing factors which determine susceptibility to air pollution is an important step in understanding the distribution of risk in a population and is critical for setting appropriate policies. We evaluate general and specific measures of community health as modifiers of risk for asthma and congestive heart failure following an episode of acute exposure to wildfire smoke.MethodsA population-based study of emergency department visits and daily concentrations of fine particulate matter during a wildfire in North Carolina was performed. Determinants of community health defined by County Health Rankings were evaluated as modifiers of the relative risk. A total of 40 mostly rural counties were included in the study. These rankings measure factors influencing health: health behaviors, access and quality of clinical care, social and economic factors, and physical environment, as well as, the outcomes of health: premature mortality and morbidity. Pollutant concentrations were obtained from a mathematically modeled smoke forecasting system. Estimates of relative risk for emergency department visits were based on Poisson mixed effects regression models applied to daily visit counts.ResultsFor asthma, the strongest association was observed at lag day 0 with excess relative risk of 66%(28,117). For congestive heart failure the excess relative risk was 42%(5,93). The largest difference in risk was observed after stratifying on the basis of Socio-Economic Factors. Difference in risk between bottom and top ranked counties by Socio-Economic Factors was 85% and 124% for asthma and congestive heart failure respectively.ConclusionsThe results indicate that Socio-Economic Factors should be considered as modifying risk factors in air pollution studies and be evaluated in the assessment of air pollution impacts.

Cardiovascular and Cerebrovascular Emergency Department Visits Associated With Wildfire Smoke Exposure in California in 2015

“…For example, we did not examine the effect of personal traits or characteristics such as socioeconomic status, past medical history, race, sex and other factors that may modify the association between daily variation in smoke exposure and ED visits. The modifying effect of these factors has previously been observed and discussed in the literature 11, 25, 54. However, we did examine the sensitivity of these results to the confounding by socioeconomic status, such as poverty, and did not find evidence of confounding between poverty, smoke exposure, and health outcomes (Table S3).…”

Changes in weather and climate extremes: State of knowledge relevant to air and water quality in the United States

“…Figure 6 shows that the majority of the acres are burned during the summer months. The smoke from wildfires is a serious medical hazard (e.g., Shusterman et al, 1993;Rappold et al, 2012). Additionally, it can reduce visibility on a local scale (Peterson et al, 2008b).…”

Climate Change. A Global Threat to Cardiopulmonary Health

“…During the Russian heat wave of 2010, for instance, smoke from more than 500 wildfires stretched across more than 1,800 milesroughly the distance from San Francisco to Chicago (30). Studies in the United States, Europe, and Australia have associated exposure to wildland fire smoke with asthma and COPD exacerbations and hospitalizations (31,32), congestive heart failure events (33), and overall mortality (34).…”