Occupational exposure assessment of phthalate esters in indoor and outdoor microenvironments.

Phthalate esters (PAEs) are widely used as plasticizers in consumer products. PAEs are a group of environmental hormone which disrupts human and animals' endocrine systems. Different occupational groups are exposed to various levels of PAEs. In the present study, four typical occupational groups were chosen, including doctors, college teachers, college students, and drivers who worked in public traffic system. In order to understand the exposure levels to PAEs via inhalation, air samples were collected from multiple microenvironments including indoor and outdoor in Hangzhou to measure the gas and particle concentrations of six PAEs, together with time spent in different microenvironments of these four groups. A comprehensive PAEs exposure model was built to estimate the daily PAEs exposure through inhalation, oral and dermal pathways. The Monte Carlo simulation results show that doctors were exposed to the highest level of PAEs, and consequently had the highest health risk among these four occupational groups. In contrast, college students had the lowest health risk. By setting the exposure level of staying in residences as the baseline, doctors and drivers were two occupations exposed to high PAEs health risk. Di-(2-ethylhexyl) phthalate (DEHP) was the largest contributor among the six phthalates, posing moderate health risk (10-5-10-6) to every occupation. For traffic microenvironments alone, the total exposure levels for different transportation modes were in the descending order of busses, cars, cabs, tubes, motor bikes, and walking.

Concentrations and risk assessment of selected monoaromatic hydrocarbons in buses and bus stations of Hangzhou, China.

Air pollution surveys of ten selected monoaromatic hydrocarbons (MAHCs) were conducted in buses and bus stations in Hangzhou, China. The mean concentrations of MAHCs in the air of buses and bus stations were 95.9 and 36.5 microg/m(3), respectively, of which toluene was the highest in all the sampling sites. Mean concentrations of all MAHCs in buses were statistically higher than those nearby bus stations (p<0.05). MAHCs concentrations in buses largely depend on vehicle conditions (including vehicle type, fuel type, interior decoration, etc.) and traffic conditions (mainly traffic density). Among the investigated buses, microbuses had the highest MAHCs level, while electric buses had the lowest. Buses driven in downtown had the highest MAHCs level, followed by those in suburban areas and tourist areas. The mean concentration ratio of toluene to benzene was 2.1+/-0.9, indicating that vehicle emission was the dominant source of MAHCs. Interior decorations, such as painting and surface coating, could also contribute to the MAHCs in the buses. The mean lifetime carcinogenic risks for passengers and bus drivers were 1.11x10(-5) and 4.00x10(-5), respectively, which were way above the limit set by USEPA. The health risk caused by MAHCs in bus microenvironment should be cautioned.

[PAHs pollution in air of coke plant and health risk assessment].

12 PAHs in air of different production sector in coking plant were measured with the result showing that, the total PAHs concentrations ranged from 11.75 to 46.66 micrograms/m3, among which, BaP was 0.050-1.054 micrograms/m3 descending following the order: the outlet of coke oven, the top of coke oven, the gate, the point of flaming out coke. BaP pollution in air of the top and the outlet of coke oven were much heavier than in the soot and in air of arterial road. The toxic equivalency factors (TEF) adjusted concentrations of total PAHs were 0.3875-1.714 micrograms/m3, and in this way, workers' daily exposure to PAHs were 3.100-13.71 micrograms/m3.