Levels, sources and health risks of carbonyls and BTEX in the ambient air of Beijing, China.

Levels, sources and health risks of carbonyls and BTEX in the ambient air of Beijing, China.

Journal of environmental sciences (China) (2012-07-13)

Yujie Zhang, Yujing Mu, Junfeng Liu, Abdelwahid Mellouki

ABSTRAKT

The atmospheric concentrations of carbonyls and BTEX (benzene, toluene, ethylbenzene, m,p-xylene and o-xylene) were measured simultaneously at a same sampling site in Beijing from September 2008 to August 2010. The average concentrations of the total measured carbonyls during autumn, winter, spring, and summer were 37.7, 31.3, 39.7, 50.5 microg/m3, respectively, and maximal values for their diurnal variations usually happened at noontime. In contrast to carbonyls, the average concentrations of the total measured BTEX during the four seasons were 27.2, 31.9, 23.2, 19.1 microg/m3, respectively, and minimal values for their diurnal variations always occurred in the early afternoon. The average concentration for carbonyls increased about 24% from September 2008-August 2009 to September 2009-August 2010, for BTEX, increased about 15%. Integrated life time cancer risks for three carcinogens (benzene, formaldehyde and acetaldehyde) in Beijing exceeded the value of 1E-06, and the hazard quotient (HQ) of non-cancer risk of exposure to formaldehyde exceeded unity.

MATERIAŁY

Numer produktu

Marka

Opis produktu

733768

Sigma-Aldrich

Ethylbenzene solution, suitable for NMR (reference standard), 10% in chloroform-d (99.8 atom % D), NMR tube size 10 mm × 8 in.

710725

Sigma-Aldrich

Ethylbenzene solution, suitable for NMR (reference standard), 5% in chloroform-d (99.8 atom % D), TMS 1 %, NMR tube size 5 mm × 7 in.

95670

Supelco

m-Xylene, analytical standard

551341

Sigma-Aldrich

Ethylbenzene solution, suitable for NMR (reference standard), 5% in chloroform-d (99.8 atom % D), TMS 2 %, NMR tube size 5 mm × 8 in.

714917

Sigma-Aldrich

Ethylbenzene solution, suitable for NMR (reference standard), 0.1% in chloroform-d (99.8 atom % D), TMS 0.01 %, NMR tube size 5 mm × 8 in. , ultra-thin wall

487120

Sigma-Aldrich

Ethylbenzene solution, suitable for NMR (reference standard), 0.1% in chloroform-d (99.8 atom % D), TMS 0.01 %, NMR tube size 8 mm × 8 in.

612480

Supelco

Ethylbenzene solution, suitable for NMR (reference standard), 0.1% in chloroform-d (99.8 atom % D), chromium(III) acetylacetonate 0.1 mg/mL, TMS 0.01 %, NMR tube size 5 mm × 8 in.

487104

Supelco

Ethylbenzene solution, suitable for NMR (reference standard), 0.1% in chloroform-d (99.8 atom % D), TMS 0.01 %, NMR tube size 5 mm × 8 in.

PHR1313

Supelco

m-Xylene, Pharmaceutical Secondary Standard; Certified Reference Material

736198

Supelco

Ethylbenzene solution, suitable for NMR (reference standard), 10% in chloroform-d (99.8 atom % D), NMR tube size 5 mm × 8 in. , ultra-thin wall

708054

Sigma-Aldrich

Ethylbenzene solution, suitable for NMR (reference standard), 0.1% in chloroform-d ("100%", 99.96 atom % D)