Assessment of environmental gamma radiation dose rate in ardabil and sarein in 2009

Gamma rays, the most energetic photons within the any other wave in the electromagnetic spectrum, pose enough energy to form charged particles and adversely affect human health. Provided that the external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined, environmental gamma dose rate and corresponding annual effective dose were determined in the cities of Ardabil and Sar Ein. Outdoor environmental gamma dose rates were measured using an Ion Chamber Survey Meter in 48 selected locations [one in city center and the remaining in cardinal and ordinal directions] in Ardabil and Sar Ein. Ten more locations were monitored along the hot springs effluent in Sar Ein. Measurements of gamma radiation dose rate were performed at 20 and 100 cm above the ground for a period of one hour. Average outdoor environmental gamma dose rate were determined as 265, 219, and 208 nSvh[-1] for Ardabil, Sar Ein, and along the hot spring effluent, respectively. The annual affective dose for Ardabil and Sar Ein residents were estimated to be 1.45 and 1.39 mSv, respectively. Calculated annual effective dose of 1.49 and 1.35 n5V are appreciably higher than the population weighted average exposure to environmental gamma radiation worldwide and that analysis of soil content to different radionuclide is suggested

Passive air sampling survey of polybrominated diphenyl ether in private cars: implications for sources and human exposure

In order to characterize polybrominated diphenyl ether [PBDE] contamination in vehicle interiors, airborne concentrations of polybrominated diphenyl ethers were investigated using PUF disk passive air samplers in 25 private cars. Passive air samplers were fixed inside the selected cars for a period of 4 to 6 weeks. LPBDE concentrations [sum of the 10 congeners] ranged between 0.01 and 8.2 ng/m[3] with respective arithmetic and geometric mean concentrations of 0.71 and 0.091 ng/m[3]. High concentrations of polybrominated diphenyl ethers found in cars might provide an important source of human exposure to PBDEs either via inhalation or dust ingestion. A driver spending 8 hours a day inside a contaminated car [the worst scenario] would receive a daily inhalation intake of 54 ng. Age of the vehicles was found to be the most influential factor affecting polybrominated diphenyl ether emission in car interiors [R=0.47, r<0.01]. Furthermore, significant variations were observed in polybrominated diphenyl ether concentrations between cars from same manufacturer with similar ages. The median ratio of BDE 47:99 for air samples was 1.7 comparing with the respective values of 1 and -0.7 reported for BK 70-5DE and DE-71, suggesting these commercial formulations to be likely sources of polybrominated diphenyl ethers in the car indoor environments