Isotopic evidence for acidity-driven enhancement of sulfate formation after SO2 emission control

After the 1980s, atmospheric sulfate reduction is slower than the dramatic reductions in sulfur dioxide (SO2) emissions. However, a lack of observational evidence has hindered the identification of causal feedback mechanisms. Here, we report an increase in the oxygen isotopic composition of sulfate (Δ17OSO42-) in a Greenland ice core, implying an enhanced role of acidity-dependent in-cloud oxidation by ozone (up to 17 to 27 in sulfate production since the 1960s. A global chemical transport model reproduces the magnitude of the increase in observed Δ17OSO42- with a 10 to 15 to sulfate in Eastern North America and Western Europe. With an expected continued decrease in atmospheric acidity, this feedback will continue in the future and partially hinder air quality improvements

コウガンヤク ニ ヨル バクロ ノ ジッタイ ト タイサク ノ ケントウ ガイライ カガク リョウホウ カンレン シセツ ノ カンキョウ チョウサ ヨリ

近年、抗がん薬の曝露対策の重要性が周知され、職業性曝露対策ガイドラインに基づく対策が、各施設で実施されている。CSTD 使用、PPE 装着、患者への曝露対策のオリエンテーションを実施している外来化学療法関連施設で、曝露対策効果の評価を目的とし、揮発性薬剤のシクロホスファミド・在宅で投薬をするフルオロウラシル・使用頻度の高いゲムシタビン・パクリタキセル（アルブミン懸濁型も含む）の4種類の薬剤を指標として、調製から投薬、患者の排泄までの一連の流れでの環境曝露を調査した。薬剤調製エリア、点滴準備エリアにおいては薬剤の検出があったが、治療環境では検出されず、ガイドラインに基づく薬剤師と看護師の曝露対策の効果として評価できた。患者の在宅物品である在宅ポンプ表面・廃棄袋の汚染、および患者用トイレからの薬剤検出があり、今後の曝露対策の強化の必要性が示唆された。資料Information

Plasmodium falciparum: Differential Selection of Drug Resistance Alleles in Contiguous Urban and Peri-Urban Areas of Brazzaville, Republic of Congo

The African continent is currently experiencing rapid population growth, with rising urbanization increasing the percentage of the population living in large towns and cities. We studied the impact of the degree of urbanization on the population genetics of Plasmodium falciparum in urban and peri-urban areas in and around the city of Brazzaville, Republic of Congo. This field setting, which incorporates local health centers situated in areas of varying urbanization, is of interest as it allows the characterization of malaria parasites from areas where the human, parasite, and mosquito populations are shared, but where differences in the degree of urbanization (leading to dramatic differences in transmission intensity) cause the pattern of malaria transmission to differ greatly. We have investigated how these differences in transmission intensity affect parasite genetic diversity, including the amount of genetic polymorphism in each area, the degree of linkage disequilibrium within the populations, and the prevalence and frequency of drug resistance markers. To determine parasite population structure, heterozygosity and linkage disequilibrium, we typed eight microsatellite markers and performed haplotype analysis of the msp1 gene by PCR. Mutations known to be associated with resistance to the antimalarial drugs chloroquine and pyrimethamine were determined by sequencing the relevant portions of the crt and dhfr genes, respectively. We found that parasite genetic diversity was comparable between the two sites, with high levels of polymorphism being maintained in both areas despite dramatic differences in transmission intensity. Crucially, we found that the frequencies of genetic markers of drug resistance against pyrimethamine and chloroquine differed significantly between the sites, indicative of differing selection pressures in the two areas