Association between air pollution and menstrual disorder outpatient visits: A time-series analysis.

Menstrual disorders are common diseases among reproductive-aged women with increasing concerns. Until now, there have been limited studies about the association between menstrual disorders and air pollution. This study aimed to investigate the association between short-term (concurrent day and within 1 week prior) ambient air pollution exposure and menstrual disorder outpatient visits in Xi'an, a metropolis in northwestern China. Daily baseline outpatient data of menstrual disorders from January 1, 2010 to February 18, 2016 (2239 days) were obtained. An over-dispersed Poisson generalized additive model was applied to discover the relationship between short-term air pollution exposure and the number of menstrual disorder outpatient visits by adjusting the day of the week and weather conditions. A total of 51,893 outpatient visits for menstrual disorders were recorded. A 10 µg/m3 increase of PM10 and NO2 concentrations corresponded to 0.236% (95% Cl: 0.075%, 0.397%) and 2.173% (95% Cl: 0.990%, 3.357%) elevations in outpatient-visits for menstrual disorders at lag 7 and lag 01 (concurrent day and previous 1 day), respectively. The association was more significant in young females (18-29 years) and there was no obvious association observed between SO2 and menstrual disorder outpatient visits. This is the first evidence that short-term exposure to ambient air pollution can be associated with an increased risk of menstrual disorder attacks. The results of our study may help to establish more comprehensive understanding of the health effects of ambient air pollution on menstrual disorders and other reproductive diseases.

[Minimum amounts of suitable habitat for wheat aphid, parasitoid, and hyperparasitoid in facility-based agricultural landscapes].

Minimum amount of suitable habitat (MASH) is the minimum habitat area that a population requires to persist in a given environmental setting for a long time, being an important aspect of population viability analysis (PVA). In this paper, we estimated the MASH for wheat aphids, parasitoids, and hyperparasitoids in facility-based agricultural landscapes in Yinchuan Plain of Northwest China, based on the relationships between population density and habitat area, and by using regression analysis. It was found that the population density and growth rate were consistently inversely related to area, but the exact mathematical functions varied with different species, especially those at different trophic levels. The MASH values for Macrosiphum avenae, Schizaphis graminum, Aphidius avenae, Aphidius gifuensis, and Pachyneuron aphidis were estimated with a polynormal regression model of density-area relationship, and the results were similar to those estimated from an inverse relationship between population and area. The differences of MASH between trophic levels were significant. It was concluded that these species had different values of MASH, which reflected their different habitat requirements and their differences in body size, migration, trophic position, and habitat quality. For parasitoids, the highest parasitic rates always took place at a spatial scale of 800-1000 m2, which could be considered as the base of aphids control with parasitoids, while the difference of MASH among trophic levels could be used to suppress the pest population.