Modeled methylmercury exposure and risk from rice consumption for vulnerable populations in a traditional fish-eating area in China.

The circulation of rice from contaminated areas could escalate exposure risk from a local problem to a national issue and affect a wider population beyond the region of origin, as confirmed by the "Poison Rice Incident" in May 2013 in Guangzhou, China. In the present study, the authors established a food chain model based on the aquivalence method to identify major sources of methylmercury (MeHg), estimate the levels of MeHg, and quantify exposure to MeHg via rice and aquatic food consumption. Different types of organism samples from the Haihe River also were collected to verify the calculated values.

[First flush analysis of PAHs in roof runoff in Beijing].

Roof runoff samples of six storm events were collected at three different sites in the urban area of Beijing during the rainy season of 2008. The samples were analyzed for PAHs in both particle and dissolved phases. On the basis of the field measured data, the first flush phenomenon of PAHs was quantitatively analyzed using a newly defined FF(n-Max), and the influences of the storm event characteristics were discussed.