Impact of ambient fine particulate matter (PM2.5) exposure on the risk of influenza-like-illness: a time-series analysis in Beijing, China

Abstract

BackgroundAir pollution in Beijing, especially PM2.5, has received increasing attention in the past years. Although exposure to PM2.5 has been linked to many health issues, few studies have quantified the impact of PM2.5 on the risk of influenza-like illness (ILI). The aim of our study is to investigate the association between daily PM2.5 and ILI risk in Beijing, by means of a generalized additive model.MethodsDaily PM2.5, meteorological factors, and influenza-like illness (ILI) counts during January 1, 2008 to December 31, 2014 were retrieved. An inverse Gaussian generalized additive model with log link function was used to flexibly model the nonlinear relationship between the PM2.5 (single- and multiday lagged exposure) and ILI risk, adjusted for the weather conditions, seasonal and year trends. We also assessed if the effect of PM2.5 differs during flu season versus non-flu season by including the interaction term between PM2.5 and flu season in the model. Furthermore, a stratified analysis by age groups was conducted to investigate how the effect of PM2.5 differs across age groups.ResultsOur findings suggested a strong positive relationships between PM2.5 and ILI risk at the flu season (October-April) (p-value < 0.001), after adjusting for the effects of ambient daily temperature and humidity, month and year; whereas no significant association was identified at the non-flu season (May-September) (p-value = 0.174). A short term delayed effect of PM2.5 was also identified with 2-day moving average (current day to the previous day) of PM2.5 yielding the best predictive power. Furthermore, PM2.5 was strongly associated with ILI risk across all age groups (p-value < 0.001) at the flu season, but the effect was the most pronounced among adults (age 25–59), followed by young adults (age 15–24), school children (age 5–14) and the elderly (age 60+) and the effect of PM2.5 was the least pronounced for children under 5 years of age (age < 5).ConclusionsAmbient PM2.5 concentrations were significantly associated with ILI risk in Beijing at the flu season and the effect of PM2.5 differed across age groups, in Beijing, China.

The impact of ambient fine particles on influenza transmission and the modification effects of temperature in China: A multi-city study

“…We observed that the lagged effects of PM 2.5 on the incidence of influenza can be explained by the incubation period of the influenza virus consistent with previous studies (Lessler et al, 2009). A study from Beijing showed that the effects are strongest with a 2-day moving average of PM 2.5 , while another study from Nanjing reported that the strongest effects are for the current day and for the 2-day moving average (C Feng et al, 2016;Huang et al, 2016). The difference in lag days of PM 2.5 may reflect the use of different methodologies and data sources.…”

“…Influenza cases reported in the system were defined according to national criteria and identified by both routine clinical and laboratory examination. However, under-reporting of influenza cases may have occurred, as some individuals with influenza may not have attended hospital and therefore not been captured by the hospital reporting system (C Feng et al, 2016). Another limitation of the current study is that we did not have information on some demographic and behavioural factorssuch as age, gender and cigarette smokingwhich may be associated with incident influenza .…”

The complex associations of climate variability with seasonal influenza A and B virus transmission in subtropical Shanghai, China

“…Second, the data accuracy may influenced by the sample collection and processing approaches, as well as patient health seeking behaviour (Dowell, 2001;Lofgren et al, 2007). Third, air pollutions, host susceptibility and viral migration may also affect the transmission of influenza (Dowell, 2001;Feng et al, 2016;Lofgren et al, 2007).…”

Comparison of Lung Damages Due to Petrol and Diesel Car Smoke Exposures: Histological Study

“…The allergy response was the most reported cases [22], [23]. The other circumstances were influenza-like illness [24], alveolar emphysema [25], lung cancer [26], and chronic obstructive pulmonary disease (COPD) [27]. The impacts of the vehicle emissions on lung, there is less information available, especially for the emissions from the car using a different fuel.…”