Air Pollution and Weather Conditions Are Associated with Daily Outpatient Visits of Atopic Dermatitis in Shanghai, China.

BACKGROUND: Non-optimum weather conditions and air pollution have the potential to increase the risk of atopic dermatitis (AD), but the associations are rarely evaluated, especially in developing countries. OBJECTIVE: To investigate the independent influence and interaction effects of meteorological factors and air pollutants on the onset of AD. METHODS: Daily data on outpatient visits of AD were obtained from Shanghai Dermatology Hospital and comprised 34,633 patients during the period from January 2013 to December 2018. Meteorological conditions and air pollutant concentrations in Shanghai, China, during the 6-year period were collected. We applied the overdispersed generalized additive model and the distributed lag model to explore the short-term cumulative effects of environmental factors on AD. RESULTS: AD symptoms were aggravated by extreme low temperature (1st percentile, 0.5°C) (RR = 1.32, 95% CI: 1.16-1.51) and per 10 unit decrease of humidity (RR = 1.10, 95% CI: 1.12-2.47). The increased concentration of air pollutants except ozone (O3) contributed to the increased risk of AD outpatients. A 10 µg/m3 increase in sulfur dioxide (SO2) and nitrogen dioxide (NO2) were associated with 6.03% (95% CI: 2.29%, 9.91%), and 1.96% (95% CI: 0.46%, 3.48%) increase of AD outpatients. AD patients in the 8- to 17-year-old group were most susceptible to extreme low temperature, and patients in the 0- to 7-year-old group were most susceptible to air pollutants, including particulate matter (PM10), SO2, and NO2. Men were more sensitive to the effects of extreme low temperature than women, while women were more vulnerable to air pollutants. The adverse effects of SO2 and NO2 on AD can be enhanced significantly by the warm season or other pollutants. CONCLUSION: Exposure to a lower temperature, lower humidity, and higher levels of air pollutants is significantly associated with increased risks of AD incidence. These impacts were more pronounced in children less than 7 years old, women, and warm seasons.

Impact of solar ultraviolet radiation on daily outpatient visits of atopic dermatitis in Shanghai, China.

The potential roles of solar ultraviolet radiation (UVR) as an environmental risk factor in inducing atopic dermatitis (AD) have not been well quantified. To determine the short-term associations between UVR and AD outpatient visits, we obtained daily outpatient visits of AD in Shanghai Skin Disease Hospital from 2013 to 2018. Data of hourly ground UVR were collected. We applied overdispersed generalized additive model to explore its associations. We found that daily exposure to UVR-A rather than UVR-B was positively associated with AD outpatient visits. The visits increased on the present day (lag 0 days) and decreased appreciably with longer lags and became insignificant at lag 4 days. For 10 w/m2 increase in daytime mean and noontime mean exposure to overall UVR and UVR-A from lag 0 to 6 days, the cumulative relative risk of AD was 1.12/1.13 and 1.08/1.08, respectively. Stronger effects of UVR exposure on AD occurred in patients aged 0-7 and > 45 years and in the cold seasons. This study contributed to the few epidemiological evidences that acute exposure to solar UVR may elevate the risks of AD.

Repellency of essential oils of Cryptomeria japonica (Pinaceae) against adults of the mosquitoes Aedes aegypti and Aedes albopictus (Diptera:Culicidae).

The purpose of this study was to investigate the repellent activities of essential oils from Cryptomeria japonica (sugi) against adults of mosquitoes Aedes aegypti and Aedes albopictus . Comparison of essential oils from four different plant parts of C. japonica revealed that essential oil from its leaf exhibited the best repellent activity against mosquitoes. To understand the relationship between volatile organic compounds and repellent activity, the solid-phase microextraction (SPME) method was employed to analyze volatile organic compounds of leaf essential oil. The SPME fiber was coated with divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS). The major volatile organic compounds in the cage were 3-carene, alpha-terpinene, limonene, gamma-terpinene, and terpinolene at 0 min. Results demonstrated that (-)-terpinen-4-ol was the major volatile organic compound adsorbed by SPME fiber during repellent assays. Furthermore, the repellent activities of six compounds against adults of the mosquitoes were evaluated, and the results revealed that (-)-terpinen-4-ol exhibited the best repellent activity against A. aegypti and A. albopictus.

Mosquito larvicidal activities of extractives from black heartwood-type Cryptomeria japonica.

The purpose of this study is to determine the larvicidal activities of ethanolic extracts from leaves, wood, and bark of black heartwood-type Cryptomeria japonica against fourth-instar larvae of mosquitoes Aedes aegypti and Aedes albopictus. Among three ethanolic extracts from C. japonica, wood extract exhibited the best larvicidal activity against A. aegypti and A. albopictus with LC(50) values of 63.2 and 93.8 microg/ml, respectively. Four major compounds, including ferruginol, epi-cubebol, cubebol, and isopimarol, were isolated from wood extract, and it was demonstrated that cubebol exhibited the best activity against A. aegypti and A. albopictus with LC(50) values of 60.1 and 50.0 microg/ml, respectively. Our findings showed that the wood extract and cubebol from C. japonica have good potential as a source for natural larvicides.