Exposure measurement, risk assessment and source identification for exposure of traffic assistants to particle-bound PAHs in Tianjin, China

To investigate the levels of exposure to particulate-bound polycyclic aromatic hydrocarbon （PAH） and to estimate the risk these levels pose to traffic assistants （TAs） in Tianjin （a rnegacity in North China）, a measurement campaign （33 all-day exposure samples, 25 occupational-exposure samples and 10 indoor samples） was conducted to characterize the TAs＇ exposure to PAHs, assess the cancer risk and identify the potential sources of exposure. The average total exposure concentration of 14 PAHs was approximately 2871 ＋ 928 ng/rn3 （on-duty）, and 1622 ＋ 457 ng/m3 （all-day）. The indoor PAHs level was 1257 ＋ 107 ng/m3. After 8000 Monte Carlo simulations, the cancer risk resulting from exposure to PAHs was found to be approximately 1.05 x 10-4. A multivariate analysis was applied to identify the potential sources, and the results showed that, in addition to vehicle exhaust, coal combustion and cooking fumes were also another two important contributors to personal PAH exposure. The diagnostic ratios of PAH compounds agree with the source apportionment results derived from principal component analysis.

Carbendazim residue in plant-based foods in China:Consecutive surveys from 2011 to 2020

Carbendazim,a widely used fungicide in China,has been found to have reproductive toxicity and mutagenic effects.However,information on the spatial-temporal variations of carbendazim residues in food in China is limited.Here,we investigated the presence of carbendazim in China's plant-based foods from 2011 to 2020,evaluated the spatial-temporal characteristics,and assessed the associated exposure risks in the Chinese diet.The results revealed a high detection frequency of carbendazim in fruits(26.4%)and high concentrations in vegetables(~110 mg kg^(-1)),indicating widespread misuse of the fungicide.The acute risks of consuming certain vegetables and cereals exceeded the recommended limits by up to 12 and 5 times,respectively.Although there has been a decline in carbendazim residue levels in food since the implementation of the Chinese government's action plan for zero growth of pesticide use in 2015,some provinces still exhibited high levels of carbendazim in multiple food categories,which were positively correlated with annual pesticide application.We highlight that carbendazim contamination reflects the broader issue of pesticide use in China.It emphasizes the need for committed and targeted national policies to reduce carbendazim residues in food and suggests that such measures could also regulate the use of other pesticides,given that pesticide abuse in China is not limited to specific types.We call for the re-evaluation of maximum residue limits of carbendazim,particularly in highly consumed foods such as cereals.

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

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 μg/m 3,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 μg/m 3,respectively,andminimal 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.