Ambient temperature and air pollution, and the risk of preterm birth in Tehran, Iran: a time series study

Ranjbaran, Mehdi and Mohammadi, Rasool and Yaseri, Mehdi and Kamari, Mehdi (2020) Ambient temperature and air pollution, and the risk of preterm birth in Tehran, Iran: a time series study. Complement Med Res.


Download (2MB) | Preview


Objective: The aim of the present study was to determine the relationship between temperature and air pollution, and preterm birth in Tehran, Iran. Methods: In this time series study, the daily data of preterm births, air pollution, and maximum, minimum and mean temperature from March 2015 to March 2018 were used. To evaluate the effect of air pollution and temperature with and without adjustment of their mutual effects on preterm birth in lags (days) 0–21, the Distributed Lag Non-linear Models (DLNM) was used. The relative risk (RR) was estimated for extreme, moderate and mild heat (99th, 95th, 75th percentile) and cold (1st, 5th, 25th percentile) compared with the median, and for each 10-unit increase in PM2.5, NO 2, and O3, 5-unit increase in SO2, and 1-unit increase in CO. Results: The highest RR was seen in extreme (26.9�C) and moderate (24.8�C) heat of minimum temperature on lag 0 (RR ¼ 1.17; 1.05–1.31, Adjusted RR ¼ 1.16; 1.04–1.29, RR ¼ 1.15; 1.05–1.26, Adjusted RR ¼ 1.14; 1.03–1.25, respectively). In regard of cold, the only significant effect was for maximum temperature on lags 7–9 (RR ¼ 1.02; 1.00–1.04). Each 10-unit increase in PM2.5 in Lag 0 (RR ¼ 1.008; 1.001–1.014) and lag 1 (RR ¼ 1.004; 1.001–1.007) and in NO2 in lag 0 (RR ¼ 1.006; 1.000–1.012) had significant effects. Conclusion: Maternal exposure to a minimum daily temperature of 26.9 and 24.8�C compared to 13.2�C increased the risk of preterm birth by 17 and 15% on the same day, respectively. This risk increased by 0.8 and 0.6%, on the same day for each 10-unit increase in PM2.5 and NO2, respectively.

Item Type: Article
Subjects: R Medicine > RJ Pediatrics > RJ101 Child Health. Child health services
Divisions: Faculty of Medicine, Health and Life Sciences > School of Medicine
Depositing User: samira sepahvandy
Date Deposited: 02 May 2020 07:23
Last Modified: 02 May 2020 07:23

Actions (login required)

View Item View Item