Changes in cardiovascular mortality during a 2002 port strike in Southern California

Background: Increases in ambient air pollution during the 2002 Los Angeles/Long Beach port strike have been attributed to idling ships. Our objective was to evaluate the association between changes in air quality during the port strike and related cardiovascular mortality among residents living in proximity to the ports.

Methods: An ecological study examined all cardiovascular and other non-injury deaths during the 11-day strike and baseline period (20 days pre- and post-strike) occurring in residents 35 years and older living in zip codes within 8 miles of the ports. Mortality data were obtained from the California Department of Health Services. Pollution and meteorological data were obtained from CARB. Pollutant concentrations and mean daily deaths were compared during the strike and baseline periods. Generalized estimating equations were used to investigate the association between the strike period and changes in pollutant concentrations and daily mortality.

Results: During the strike period, the average number of daily cardiovascular deaths increased from 2.70 to 4.27 (p<0.01) while there were no significant differences detected in other non-injury deaths. Concentrations of fine particulate matter, oxides of nitrogen and carbon monoxide increased 43%, 18%, and 42% during the strike, respectively. The adjusted rate ratio for cardiovascular deaths was 1.50 (95% CI: 1.01, 2.25) during the strike while risk for other non-injury deaths did not change. Several pollutants were significantly associated with cardiovascular death (p<0.05).

Conclusions: The results indicate that idling ships may be associated with increased pollution and cardiovascular deaths, highlighting the importance of reducing emissions near harbor communities.