Petroleum refineries have been considered as an important emission source for atmospheric volatile hazardous air pollutants(HAPs). The emission source includes petroleum refinery processes and process equipment. The control strategy for volatile HAPs requires emission estimations of these pollutants. However, systematic methods of volatile HAPs emission from petroleum refineries have not yet been established. Accordingly, present study surveyed the estimation method of volatile HAPs emitted from the petroleum refinery processes and process equipment. The emission estimation methods for the petroleum refinery processes are applied for 11 petroleum refining facilities: fluidized catalytic cracking, thermal cracking, moving bed catalytic cracking, compressed engine, blowdown system, vacuum distilled column condensator, natural gas or distilled boiler, natural gas or distilled heater, oil boiler, oil heater and flare. Four emission estimation methods applied for the petroleum refinery process equipment are as follows: average emission factor approach, screening ranges approach, EPA correlation approach and unit-specific correlation approach. The process equipment for which emission factors are available are valves, pump seals, connectors, flanges and open-ended lines.

Evaluated were household THMs exposure associated with the use of municipal tap water treated with chlorine and with ozone-chlorine. The current study measured the THMs concentrations in the tap water and indoor and outdoor air in the two types of household, along with an estimation of THMs exposure from water ingestion, showering, and the inhalation of indoor air. Chloroform was the most abundant THMs in all three media, yet no bromoform was detected in any sample. Contrary to previous findings, the fall water THMs concentrations exhibited no significant difference between the chlorine and ozone-chlorine treated water. However, the spring median chloroform concentration in the tap water treated with chlorine (17.6 ppb) was 1.3 times higher than that in the tap water treated with ozone-chlorine (13.4 ppb). It is suggested that the effects of the water parameters should be considered when evaluating the advantage of ozone-chlorine disinfection for THMs formation over chlorine disinfection. The indoor air THMs concentration trend was also consistent with the water concentration trend, yet the outdoor air THMs concentrations did not differ significantly between the two types of household. The indoor to outdoor air concentration ratios were comparable with previous studies. The THMs exposure estimates from water ingestion, showering, and the inhalation of indoor air suggested that, for the residents living in the surveyed households, their exposure to THMs in the home was mostly associated with their household water use, rather than the indoor air. The THMs exposure estimates from tap water ingestion were similar to those from showering.