AIM To explore the molecular mechanism of hydroquinone genotoxicity in human bronchial epithelial cells and investigate whether human X-ray repair cross complementing group 1 (XRCC1)was involved in protecting cells from the damage caused by hydroquinone. METHODS XRCC1 gene was knocked down by RNA interference and XRCC1-deficient cell was established by transfected recombinant plasmid pEGFP-C1-pU6-dsRNA. Normal human bronchial epithelial cells (normal cells) and cells transfected with the empty vector of pEGFP-C1 (vector cells) were used as the normal control and vector control. All cells were treated with different concentrations of hydroquinone (10-100 μmol·L-1) for 4 h. MTT assay was used to test cell viability and comet assay was used to detect the DNA damage and repairment. RESULTS MTT assay showed that hydroquinone inhibited the growth of cells in a concentration-dependant manner and the survival number of XRCC1-deficient cell was less than that of the two control groups. Comet assay revealed that different concentrations of hydroquinone caused more severe DNA damage in XRCC1-deficient cell line than in control cells and there were no significant difference in the two control groups. CONCLUSION The results suggest XRCC1 be involved in preventing cells from damage caused by hydroquinone.

Objective: To evaluate the intervention effects of response to heatwave in communities of four cities, China. Methods: Baseline survey on heatwave and climate change related knowledge, attitude and practice (KAP) was conducted in the pilot communities in Harbin, Nanjing, Shenzhen and Chongqing, using face-to-face questionnaire interview in November, 2011 to November, 2013. Finally, 1 604 residents were interviewed. Intervention measures were implemented in summers of 2013 and 2014, including delivering early warning information of heatwave health risk and launching health education and promotion. The second survey was conducted in same communities using the same questionnaire and sampling method as baseline survey in November, 2014, and 1 640 residents were interviewed. The Chi-square test was used to compare the demographic characteristics and KAP of community residents between before and after intervention, and the factors that affected the intervention effect were selected by logistic multiple stepwise regression model. Results: The age of the residents interviewed before and after intervention was (46.4 ± 15.5) years and (45.0 ± 15.9) years, respectively. Overall, the residents' awareness rates of heatwave before and after intervention were 70.5% (1 131/1 604) and 82.9% (1 359/1 640) (χ²=69.40, P<0.001). The rate of residents who had wished to receive early warning information increased 6.3% (χ²=41.11, P<0.001), which reached 94.6% (1 551/1 604) after intervention from 88.3% (1 416/1 604) in baseline survey. Both heatwave health risk early warning and health education had big impacts to residents. There were 92.7% (1 105 residents) among the 1 192 residents who had received the early warning information arrange work and rest time according to the early warning information and 93.0% (1 231 residents) among the 1 323 residents who knew about health education activities being conducted in community thought that the community health education activities had made active role in protecting health from heatwaves. After a series of intervention, male had a effect on attitude about hot wave than female in Nanjing and Chongqing, OR (95%CI) were 1.48(1.02-2.16) and 1.45 (1.18-2.05) , respectively; compared with subjects below primary school education, people with college degree or above had higer KAP in all cities (ORs range from 1.18 to 2.05), P<0.05; regular physical exercise (ORs range from 1.39 to 2.70) also had profound impacts on KAP in all cities (P<0.05). Conclusion s Early warning and health education were effective measures to enhance residents' response capacity to climate change.