September 19, 2022
2 minute read
Key points to remember:
- The greatest effects of particulates and nitrogen dioxide on allergic rhinitis outpatients occurred on daytime 0.
- Every 10 µg/m3 increased sulfur dioxide concentrations were associated with a 7.69% increase in daily outpatient visits for allergic rhinitis.
- There was a negative correlation between the risk of daily outpatient visits for allergic rhinitis and temperatures below 16.4°VS
According to a letter published in Allergy.
Although most previous studies of these associations have been conducted in single cities at mid-latitudes, this study focused on three cities in a low-latitude region, Xin Luo, from the Departments of Allergy and Otorhinolaryngology-Head and Neck Surgery, Third Affiliate Hospital of Sun Yat-Sen University, Guangzhou, China, and colleagues wrote.
Researchers looked at data from 178,692 daily outpatient visits for allergic rhinitis in China’s Guangdong-Hong Kong-Macau Greater Bay Area from 2014 to 2019, in addition to air pollution and weather data. .
By calculating the main and lagged effects of air pollutants and meteorological factors during these visits, the researchers found that the 2.5 µm particles (PM2.5) and 10 µm (PMten) and nitrogen dioxide (NO2) had the largest effects on daily allergic rhinitis outpatient visits at lag day 0. Sulfur dioxide (SO2) had its strongest effects on these visits on the second lag day, and the strongest effects for the maximum 8-hour moving average ozone (O3_8h) were at lag day 3.
Cumulatively, N/A2NOPE2 and O3_8h had their strongest effects on lag days 0 to 5, while PM2.5 and PMten had their strongest effects on lag days 0 to 6.
Each 10 µg/m3 increase in SO2 was associated with a 7.69% (95% CI, 1.04% to 14.78%) increase in daily outpatient visits for allergic rhinitis. The same increase in NO2 concentration was associated with a 2.43% (95% CI, 1.31% to 3.56%) increase in visits.
Similarly, each 10 µg/m3 increased MP2.5 was associated with an increase of 1.84% (95% CI, 0.67% to 3.02%). For PMtenthis was an increase of 1.55% (95% CI, 1.04%-2.05%), and for O3_8h, it was 0.34% (95% CI, 0.1%-0.58%).
According to age group, older people were more susceptible to PM2.5 and PMtenand adolescents and young adults were more sensitive to SO2NOPE2 and O3_8h.
There was an almost S-shaped exposure-response curve for wind speed that increased sharply at concentrations below 4.5 µg/m3 and above 8 µg/m3 and flattened between those points, the researchers continued.
Additionally, the researchers found a steep slope across the range of the relative humidity exposure-response relationship curve and an almost U-shaped curve with no statistical significance for sunshine duration.
The researchers also found negative correlations between the risk of daily visits and the temperature when it was below 16.4°C. Both men and women were sensitive to low temperatures, although adolescents and young adults were more vulnerable than children and older adults (RR=1.57; 95% CI, 1.11-2, 21).
Windless conditions in extreme weather conditions appeared to have a greater effect on children, adolescents and young adults, but these differences did not reach statistical significance, the researchers wrote. Compared to men, women were more sensitive to windless (RR=1.11; 95% CI, 1.02-1.21) and windy (RR=1.75; 95% CI, 1.01) conditions. -3.01).
Women (RR=1.69; 95% CI, 1.03-2.76) and adolescents and young adults (RR=1.74; 95% CI, 1.06-2.87) suffered statistically significant effects due to dry weather. Finally, the researchers wrote, all groups except the elderly were mildly sensitive to sunny or cloudy weather.