Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in air (using PUF disk passive samplers) in 31 homes, 33 offices, 25 cars, and 3 public microenvironments. Average concentrations of sigmaBDE (273 pg m(-3)) and sigmaPCB (8920 pg m(-3)) were an order of magnitude higher than those previously reported for outdoor air. Cars were the most contaminated microenvironment for sigmaBDE (average = 709 pg m(-3)), but the least for sigmaPCB (average = 1391 pg m(-3)). Comparison with data from a previous spatially consistent study, revealed no significant decline in concentrations of sigmaPCB in indoor air since 1997-98. Concentrations in indoor dust from 8 homes were on average 215.2 ng sigmaBDE g(-1), slightly higher than other European dust samples, but twenty times lower than Canadian samples. Inhalation makes an important contribution (between 4.2 and 63% for adults) to overall UK exposure to sigmaPCB. For sigmaBDE, dust ingestion makes a significant but--in contrast to Canada-a not overwhelming contribution (up to 37% for adults, and 69% for toddlers). Comparison of UK and Canadian estimates of absolute exposure to sigmaBDE suggest that differences in dust contamination are the likely cause of higher PBDE body burdens in North Americans compared to Europeans.

Concentrations and chiral signatures of polychlorinated biphenyls (PCBs) were measured in outdoor air (using polyurethane foam (PUF)--disk passive samplers) and surface soil samples taken at approximately monthly intervals over 1 year at 10 locations on a rural-urban transect across the West Midlands of the U.K. In both air and soil, concentrations clearly decrease with increasing distance from the city center, supporting the existence of an urban "pulse", that indicate the West Midlands conurbation to be a source of PCBs to the wider environment. Concentrations of PCBs in outdoor air samples in this study are well below those reported previously for indoor air in the West Midlands. This, combined with comparison of chiral signatures in outdoor air and soil with those in samples of indoor air taken in the West Midlands, suggest strongly that the principal contemporary source of PCBs in this conurbation is ventilation of indoor air and not volatilization from soil. Future reductions in PCB concentrations in outdoor air and ultimately human exposure appear best achieved by action to remove remaining sources of PCBs from existing structures.

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Airborne concentrations of PCBs and PBDEs were measured in offices, homes, public environments, and cars. Variations in concentrations between different rooms in the same domestic and office buildings, showed some intra-building variability for both compound groups. Stepwise multiple linear regression analysis revealed no clear and consistent relationships between log-normalized concentrations of PCBs and PBDEs in homes and offices and factors such as the number of personal computers. This is considered to reflect the complexity of relationships between indoor air contamination and microenvironment characteristics. The influence of personal computers was demonstrated when PBDE concentrations in one office fell appreciably following the exchange of a computer constructed in 1998 for one dating from 2003. Concentrations of PCBs in buildings constructed between 1950 and 1979 were significantly higher (p < 0.001) than in those constructed since. When two of the most contaminated cars were omitted as outliers, a significant (p < 0.01) positive linear relationship was detected between PBDE concentrations and vehicle age. Concentrations of PCBs and PBDEs were monitored throughout a calendar year in four homes and four offices. Although concentrations in warmer months usually exceeded those in colder months, seasonal variability in indoor contamination appears less significant than observed previously for outdoor air.

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This study aimed to assess workers' exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) compounds in refueling stations of Ardabil city (Iran). Twenty-four refueling stations including 15 petrol and 9 compressed natural gas (CNG) stations from different regions were selected and monitored for ambient BTEX concentrations. Air samples were taken based on NIOSH Manual of Analytical Method no 1501. Target compounds were extracted using CS 2 and analyzed by GC equipped with FID. Average concentrations of benzene, toluene, ethylbenzene, and xylene were obtained 2.01, 1.80, 2.72, and 1.65 mg/m 3 , respectively. Benzene concentrations exceeded the occupational exposure limit set by the Iran Ministry of Health and Medical Education. Its concentrations were significantly higher in commercial areas (2.72 mg/m 3 ) compared to suburban areas (1.89 mg/m 3 ). BTEX concentrations in gasoline stations were slightly, but not significantly, higher than those in CNG stations. Long-term exposure cancer risk of 1884×10 −6 ±390× 10 −6 and hazard index of 22.83±3.66 were estimated for benzene and BTEX compounds, respectively. The results declare the necessity for controlling BTEX emission (mainly benzene) and monitoring employee's exposure in refueling stations.