Spatial and temporal distributions of contaminants emitted because of Chinese New Year's Eve celebrations in Wuhan
Activities involving firecrackers and fireworks on Chinese New Year's Eve (NYE) are common in Chinese culture. Previous studies revealed that such human activities significantly influence the ambient air quality and negatively impact human health. However, both the academia and the public lack a deep understanding of the extent and consequences of such human-induced air pollution. Therefore, it is important to evaluate the effects of these Spring Festival celebrations on ambient air quality at a large spatial scale and a fine temporal resolution. Data from ten monitoring stations distributed around Wuhan and a Lidar system provide a good opportunity to gain insight into spatial and temporal distribution of contaminants due to the NYE celebrations. Dramatic increases in PM2.5 and PM10 mass concentrations due to NYE celebrations were observed in this study. Moreover, the ratio of residential to total area was found to be a significant factor in predicting the geographic distributions of contaminants. The vertical distribution of such human-induced and culture-related contaminants was first shown using a Mie Lidar. Contaminants emitted by firecrackers on the ground spread to a distance of over 450 m in the atmosphere. The vertical influence began to fade two hours after celebrations because of dry deposition. Moreover, it took over 15 hours for the contaminant levels to return to pre-celebration levels. Finally, estimations of PM2.5 emissions from firecrackers in Wuhan were 39.57 and 43.51 tons, based on regression and time series analyses, respectively.