Assessing the association between meteorological factors and mental disorders in summer using Mesonet, a refined weather monitoring system, in New York State

Abstract

Background While the mental health impacts of temperature and humidity have been reported in some studies, little is known about the impact of solar radiation, precipitation, or the joint effect of multiple meteorological factors. Furthermore, existing studies were usually based on weather observations from limited monitoring sites. This study aimed to investigate both the independent and joint effects of multiple weather factors on mental disorders based on high-resolution weather data from Mesonet.Methods In this time-stratified case-crossover study, we evaluated the association of mental disorders with temperature, relative humidity, solar radiation, and precipitation while controlling for PM2.5, O3, and holidays using conditional logistic regression. Weather data (2017) was obtained from 126 Mesonet sites, a refined and comprehensive weather monitoring system. Outpatient records for mental disorders during summer were obtained from the New York State discharge data and assigned the weather measures from the nearest site. We assessed both the independent and joint effects of extreme conditions (>90th) of these weather factors.Results All extreme weather conditions, including temperature, solar radiation, precipitation, and humidity, significantly increased excess risks (ER%) for mental disorders on lag 3-4 days in summer, with ERs range from 7.7% to 14.9%. However, we observed a protective effect on the same day with high solar radiation. The joint effect of the extreme conditions of temperature, solar radiation, and humidity showed the highest ER% (18.5%, 95% CI: 4.7%-34.1%) for mental disorders. The risk of mental disorders increased dramatically when temperature exceeded 79 ºF, solar radiation 977 W/m2, precipitation 0.88 inches, and relative humidity 89%.Conclusions Our findings indicate a strong joint effect from temperature, solar radiation and humidity on mental disorders. Humidity had the greatest impact of all individual weather factors. The thresholds we identified will help public health preparedness planning.