Identification of atmospheric emerging contaminants from industrial emissions: A case study of halogenated hydrocarbons emitted by the pharmaceutical industry.

With the development of the pharmaceutical industry, halogenated hydrocarbons, which are the main raw materials and emissions of the pharmaceutical industry, may be defined as atmospheric emerging contaminants due to toxicity and low oxidation of the atmosphere. This study analyzed the volatile organic compounds (VOCs) emissions from four pharmaceutical companies located in the Yangtze River Delta. Samples were taken three times at each of the selected fixed and fugitive sampling sites in each company. Through testing, 141 VOCs were identified. The mean concentration and proportion of halogenated hydrocarbons from the four pharmaceutical companies were the highest of all the industries in the industrial park. They reached 18.9 ppm and 28.8 %, respectively. Fixed emissions of the companies exhibited the mean maximum concentration of dichloromethane and chlorobenzene, which are 11.4 ppm and 250.67 ppb. The mean concentration of fugitive emission of dichloromethane from the four companies in this study is lower than that of pharmaceutical companies in other studies. Newly detected halogenated hydrocarbons, such as 1,1-dichloropropanone and dichloronitromethane, present potential non-cancer and cancer risks to workers. Chlorobenzene was identified as a key potential cancer risk halogenated hydrocarbon the value of which reaches 0.00965. 2,6-dichloropyridine could be a potential emerging contaminant due to its lower MIR value and higher potential cancer risk. The study suggests that relevant pharmaceutical companies focus on the emissions of chlorobenzene and dichloromethane, which may be the atmospheric emerging contaminants for the pharmaceutical industry and focus on improve the treatment of waste gases in workshops and sewage stations.