Venous Thromboembolism in an Industrial North American City: Temporal Distribution and Association with Particulate Matter Air Pollution

Holly H Chiu,Peter Whittaker,Hugo Ten Cate

doi:10.1371/journal.pone.0068829

Holly H Chiu, Peter Whittaker + Show 1 more

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https://doi.org/10.1371/journal.pone.0068829

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Abstract

BackgroundEmerging evidence, mainly from Europe and Asia, indicates that venous thromboembolism (VTE) occurs most often in winter. Factors implicated in such seasonality are low temperature-mediated exacerbation of coagulation and high levels of particulate matter (PM) air pollution. However, in contrast to most European and Asian cities, particulate matter pollution peaks in the summer in many North American cities.ObjectivesWe aimed to exploit this geographical difference and examine the temporal distribution of VTE in a cold-weather, North American city, Detroit, with a summer PM peak. Our goal was thereby to resolve the influence of temperature and PM levels on VTE.MethodsOur retrospective, analytical semi-ecological study used chart review to confirm 1,907 acute, ambulatory VTE cases, divided them by location (Detroit versus suburban), and plotted monthly VTE frequency distributions. We used Environmental Protection Agency data to determine the temporal distribution of PM pollution components in Detroit. Suburban PM air pollution is presumed negligible and therefore not monitored.ResultsAcute VTE cases in Detroit (1,490) exhibited a summer peak (June 24th) and differed from both a uniform distribution (P<0.01) and also that of 1,123 no-VTE cases (P<0.02). Levels of 10 µm diameter PM and coarse particle (2.5 to 10 µm) PM also exhibited summer peaks versus a winter peak for 2.5 µm diameter PM. Contrary to their urban counterparts, suburban cases of acute VTE (417) showed no monthly variation.ConclusionsThe summer peak of acute VTE in Detroit indicates that low temperature is not a major factor in VTE pathogenesis. In contrast, concordance of the 10 µm diameter PM, coarse particle, and the Detroit VTE monthly distributions, combined with no monthly suburban VTE variation, is consistent with a role for PM pollution. Furthermore, divergence of the VTE and 2.5 µm PM distributions suggests that particle size may play a role.

Highlights

Acute and long-term exposure to air pollution can exert adverse effects on cardiovascular health [1]
The summer peak of acute venous thromboembolism (VTE) in Detroit indicates that low temperature is not a major factor in VTE pathogenesis
Divergence of the VTE and 2.5 mm particulate matter (PM) distributions suggests that particle size may play a role

Summary

Introduction

Acute and long-term exposure to air pollution can exert adverse effects on cardiovascular health [1]. Air pollution takes many forms, its cardiovascular effects have generally been attributed to particulate matter (PM) and, different sizes of PM. Because such particles are usually irregularly shaped, they are characterized by aerodynamic diameter rather than geometric diameter and are divided into three categories; fine particles with diameter less than 2.5 mm (PM2.5), those with diameter less than 10 mm (PM10), and coarse particles (PM10– PM2.5). Mainly from Europe and Asia, indicates that venous thromboembolism (VTE) occurs most often in winter Factors implicated in such seasonality are low temperature-mediated exacerbation of coagulation and high levels of particulate matter (PM) air pollution. In contrast to most European and Asian cities, particulate matter pollution peaks in the summer in many North American cities

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