Changes in the hospitalization and ED visit rates for respiratory diseases associated with source-specific PM2.5 in New York State from 2005 to 2016

Prior work found increased rates for emergency department (ED) visits for asthma and hospitalizations for chronic obstructive pulmonary disease per unit mass of PM₂.₅ across New York State (NYS) during 2014–2016 after significant reductions in ambient PM₂.₅ concentrations had occurred following implementation of various policy actions and major economic disruptions. The associations of source-specific PM₂.₅ concentrations with these respiratory diseases were assessed with a time-stratified case-cossover design and logistic regression models to identify the changes in the PM₂.₅ that have led to the apparently increased toxicity per unit mass. The rates of ED visits and hospitalizations for asthma and COPD associated with increases in source-specific PM₂.₅ concentrations in the prior 1, 4, and 7 days were estimated for 6 urban sites in New York State. Overall, there were similar numbers of significantly increased (n = 9) and decreased rates (n = 8) of respiratory events (asthma and COPD hospitalizations and ED visits) associated with increased source-specific PM₂.₅ concentrations in the previous 1, 4, and 7 days. Associations of source-specific PM₂.₅ concentrations with excess rates of hospitalizations for COPD for spark- and compression ignition vehicles increased in the 2014–2016 period, but the values were not statistically significant. Other source types showed inconsistent patterns of excess rates. For asthma ED visits, only biomass burning and road dust showed consistent positive associations with road dust having significant values for most lag times. Secondary nitrate also showed significant positive associations with asthma ED visits in the AFTER period compared to no associations in the prior periods. These results suggest that the relationships of asthma and COPD exacerbation with source-specific PM₂.₅ are not well defined and further work will be needed to determine the causes of the apparent increases in the per unit mass toxicity of PM₂.₅ in New York State in the 2014-16 period.