Abstract
BACKGROUND: The incidence of other infectious diarrhea (OID) is rising, imposing a significant medical burden. While meteorological factors affect OID, few studies have examined sulfur dioxide (SO(2)) or its interactions with these variables. METHODS: Using quasi-Poisson and distributed lag non-linear models, we analyzed the lagged, non-linear effects of meteorological factors and SO(2) on OID cases in Fuzhou, China (2015-2019). Interactive effects between SO(2) and meteorological variables were evaluated using multiplicative terms, multiplicative scale, relative excess risk due to interaction (RERI), and attributable proportion (AP). Stratified analyses highlighted vulnerable groups. RESULTS: The relationship between OID and mean temperature (MT), mean relative humidity (MRH) and SO(2) were represented by U-, L-, and J-shaped curves, respectively. A synergistic effect was found between MT and MRH, where low levels of both increased OID risk, while SO(2) and MT showed an antagonistic effect, with high SO(2) and low MT raising OID risk. Children aged 3-4 years were particularly sensitive to extremely low MT. CONCLUSION: These results underscore the importance roles of MT, MRH, and SO(2) in OID risk, and highlight the need for prediction and prevention strategies targeting the co-exposure of environmental factors.