Implications of 1.5 K climate warming on warm-season ozone exposure and atmospheric oxidation capacity in China

Surface ozone(O_(3))poses significant threats to public health,agricultural crops,and plants in natural ecosystems.Global warming is likely to increase future O_(3)mainly by altering atmospheric photochemical reactions and enhancing biogenic volatile organic compound(BVOC)emissions.To assess the impacts of the future 1.5 K climate target on O_(3)concentrations and ecological O_(3)exposure in China,numerical simulations were conducted using the CMAQ(Community Multiscale Air Quality)model during April-October 2018.Ecological O_(3)exposure was estimated using six indices(i.e.,M7,M24,N100,SUM60,W126,and AOT40f).The results show that the temperature rise increases the MDA8 O_(3)(maximum daily eight-hour average O_(3))concentrations by∼3 ppb and the number of O_(3)exceedance days by 10-20 days in the North China Plain(NCP),Yangtze River Delta(YRD),and Sichuan Basin(SCB)regions.All O_(3)exposure indices show substantial increases.M24 and M7 in eastern and southern China will rise by 1-3 ppb and 2-4 ppb,respectively.N100 increases by more than 120 h in the surrounding regions of Beijing.SUM60 increases by greater than 9 ppm h^(−1),W126 increases by greater than 15 ppm h^(−1)in Shaanxi and SCB,and AOT40f increases by 6 ppm h^(−1)in NCP and SCB.The temperature increase also promotes atmospheric oxidation capacity(AOC)levels,with the higher AOC contributed by OH radicals in southern China but by NO_(3)radicals in northern China.The change in the reaction rate caused by the temperature increase has a greater influence on O_(3)exposure and AOC than the change in BVOC emissions.

Basin-scale exposure risk of psychiatric pharmaceuticals and illicit drugs in tap water in Eastern China

A total of twenty-three psychiatric pharmaceuticals and illicit drugs were analyzed in tap water covering seven basins in Eastern China.The residual concentrations of these substances were detected up to 22.4 ng L^(-1).Among the substances,benzodiazepines were more often detected with higher median concentrations than those of illicit drugs.Generally,the higher residual levels of psychoactive substances were detected in the upstream of the basins compared with the downstream.For example,the concentrations of diazepam,temazepam,and oxazepam in the downstream were much higher than those in the upstream in OJ.Among the basins,YH was the most polluted region.Exposure assessment indicated the median exposure doses of diazepam and temazepam were from 85 to 99 and 3.5e4.1 pg kg^(-1) bw d^(-1) in the basins,respectively.Benchmark quotient for the nine detected substances was calculated in each basin with the range from 0.0001 to 0.0389,indicating low risk in the tap water for human health under current concentrations.