Air pollution associated with hospital visits for mental and behavioral disorders in Northeast China

Background Related studies have found that air pollution is an important factor affecting mental and behavioral disorders. Thus, we performed this time-series study to evaluate the relationship between short-term exposure to ambient air pollutants and visits to hospital by patients with mental and behavioral disorders in northeastern China. Methods We used quasi-Poisson regression models and generalized additive models to probe the links between air pollution and mental and behavioral disorders. The possible influences were also explored stratified by season, age and gender. Results We found that sulfur dioxide (SO2) had a cumulative effect on mental and behavioral disorders at lag04–lag07 and had the greatest effect at lag07 [Relative risk (RR) = 1.068, 95%CI = 1.021–1.117]. Particulate matter of size 2.5 μm (PM2.5) and SO2 had a cumulative effect on depression and both had the largest effect at lag07 (RR = 1.021, 95%CI = 1.002–1.041; RR = 1.103, 95%CI = 1.032–1.178); SO2 also had a cumulative effect on anxiety disorders, with the largest effect at lag06 (RR = 1.058, 95%CI = 1.009–1.110). In the stratified analysis, people are more susceptible in the cold season compared to the warm season and females and the 18–60-year age group are more sensitive to air pollutants. It is suggested to strengthen management and preventive measures to decrease air pollution exposure. Conclusion This study found an association between increased concentrations of air pollutants and increased outpatient visits for mental and behavioral disorders. We recommend that preventive and protective measures should be strengthened in an effort to reduce exposure to air pollution in order to maintain physical and mental health.

Note: statistically significant (P < 0.05) are indicated in bold.
Table S3.Relative risk and 95% CI of hospital admissions for anxiety disorders at different lag days for every 10 µg/m 3 increase in pollutant concentration  Note: statistically significant (P < 0.05) are indicated in bold. P value obtained from the Z-test for the difference of the effect estimates of air pollutants between seasonal groups.No differences between groups were found after Z-test.Note: statistically significant (P < 0.05) are indicated in bold. P value obtained from the Z-test for the difference of the effect estimates of air pollutants between seasonal groups.No differences between groups were found after Z-test.Note: statistically significant (P < 0.05) are indicated in bold. P value obtained from the Z-test for the difference of the effect estimates of air pollutants between seasonal groups.No differences between groups were found after Z-test.Note: statistically significant (P < 0.05) are indicated in bold. P value obtained from the Z-test for the difference of the effect estimates of air pollutants between age groups.No differences between groups were found after Z-test.Note: statistically significant (P < 0.05) are indicated in bold. P value obtained from the Z-test for the difference of the effect estimates of air pollutants between age groups.No differences between groups were found after Z-test.Note: statistically significant (P < 0.05) are indicated in bold. P value obtained from the Z-test for the difference of the effect estimates of air pollutants between age groups.No differences between groups were found after Z-test.Note: statistically significant (P < 0.05) are indicated in bold. P value obtained from the Z-test for the difference of the effect estimates of air pollutants between gender groups.No differences between groups were found after Z-test.Note: statistically significant (P < 0.05) are indicated in bold. P value obtained from the Z-test for the difference of the effect estimates of air pollutants between gender groups.No differences between groups were found after Z-test.
Table S12.Relative risk and 95% CI of hospital admissions for anxiety disorders at different lag days for every 10 μg/m 3 increase in pollutants after gender stratification Note: statistically significant (P < 0.05) are indicated in bold. P value obtained from the Z-test for the difference of the effect estimates of air pollutants between gender groups.No differences between groups were found after Z-test.
Table S13.Relative risk and 95% CI of hospital admissions for mental and behavioral disorders per 10 μg/m 3 increase in pollutants using different of freedom per year

Figure S1 .
Figure S1.Relative risk and 95% CI of hospital admissions for mental and behavioral disorders atdifferent lag days for every 10 µg/m 3 increase in pollutants after seasonal stratification

Figure S11 .
Figure S11.Exposure response curves for air pollutants and anxiety disorder.

Table S2 .
Relative risk and 95% CI of depression hospital admissions at different lag days for every 10 µg/m 3 increase in pollutant concentration

Table S4 .
Relative risk and 95% CI of hospital admissions for mental and behavioral disorders at different lag days for every 10 μg/m 3 increase in pollutants after seasonal stratification

Table S5 .
Relative risk and 95% CI of depression hospital admissions at different lag days for every 10 μg/m 3 increase in pollutants after seasonal stratification

Table S6 .
Relative risk and 95% CI of hospital admissions for anxiety disorders at different lag days for every 10 μg/m 3 increase in pollutants after seasonal stratification

Table S7 .
Relative risk and 95% CI of hospital admissions for mental and behavioral disorders at different lag days for every 10 μg/m 3 increase in pollutants after age stratification

Table S8 .
Relative risk and 95% CI of depression hospital admissions at different lag days for every 10 μg/m 3 increase in pollutants after age stratification

Table S9 .
Relative risk and 95% CI of hospital admissions for anxiety disorders at different lag days for every 10 μg/m 3 increase in pollutants after age stratification

Table S10 .
Relative risk and 95% CI of hospital admissions for mental and behavioral disorders at different lag days for every 10 μg/m 3 increase in pollutants after gender stratification

Table S11 .
Relative risk and 95% CI of depression hospital admissions at different lag days for every 10 μg/m 3 increase in pollutants after gender stratification

Table S14 .
Relative risk and 95%CI of mental and behavioral disorders from exposure to pollutants in two-pollutant models Note: statistically significant (P < 0.05) are indicated in bold.