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Background Common cold is a frequent upper respiratory tract infection, but the role of ambient temperature in the infection is unclear. Objective We investigated the role of prenatal exposure to diurnal temperature variation (DTV), the difference between the daily maximal and minimal temperatures, in the risk of common cold in children. Methods We conducted a cohort study of 2598 preschool children in Changsha, China. Occurrence of common cold during the past year was surveyed using questionnaire. We then estimated each child's prenatal exposure to DTV during pregnancy. Multivariate logistic regression model was used to examine the association between occurrence of common cold and prenatal exposure to DTV in terms of odds ratios (OR) and 95% confidence interval (CI). Results About 45% children have common cold (≥3 times) during the past year. We found that common cold in children was associated with maternal DTV exposure during pregnancy, particularly during the first trimester with adjusted OR (95% CI) = 1.27 (1.10–1.46). Male and atopic children were more susceptible to the effect of DTV during pregnancy. The risk of common cold due to DTV is higher in children living in the suburban areas and the bigger houses and in those exposed to environmental tobacco smoke, mold/dampness, new furniture and redecoration. We observed that the risk of common cold in children has been increased in recent years due to increasing DTV. Conclusions Common cold in children was associated with maternal exposure to temperature variation during pregnancy, suggesting that the risk of common cold may originate in pregnancy. [ABSTRACT FROM AUTHOR]

Numerous epidemiological studies have recently observed that exposure to traffic-related air pollution (TRAP) is associated with increased risk of various respiratory diseases. Major gaps in knowledge remain regarding the toxicological effects. We examined the toxicological effects of the gasoline exhaust particles (GEP), a paradigm of TRAP, in rats, with an objective to provide the evidence, obtain the biomarkers, and suggest effective intervention measure. We measured the airway hyperresponsiveness (AHR), inflammatory cells in the bronchoalveolar lavage (BAL) fluid, histological changes in the lung tissues, and the biomarkers so as to systematically examine the toxicological effects of GEPs at different dose levels (0.5, 2.5, 5 mg/kg BW). The intervention of vitamin E (VE), a natural antioxidant, on the toxicological effects was investigated. The lung injury caused by GEP exposure was first indicated by the airway hyperresponsiveness (AHR). Compared with the control group, GEP exposure significantly increased the airway resistances and decreased the lung compliance; the higher the dose of GEP, the more serious the lung injury. Lung injury was also revealed by the increase of inflammatory cells, including the lymphocytes and neutrophils, in the BAL fluid. With the increase of GEP dose, histological changes in the lung tissues were further observed: inflammatory cell infiltration increased and alveolar wall thickened. The toxicology of GEP was demonstrated by the increase of the biomarkers of the oxidative stress, the pro-inflammatory cytokines and the apoptosis cytokine. However, administration of VE was found to be effective in restoring airway injury. The toxicological effects of traffic-related air pollution (TRAP) on rat lungs are supported by evidence and biomarkers, and vitamin E intervention is feasible. [Display omitted] • Epidemiological studies observed that traffic-related air pollution increases the risk of respiratory diseases. • We examined the toxicological effects of the gasoline exhaust particles (GEP) on rat lungs. • We found the evidence in the airway hyperresponsiveness, the inflammatory cells in the bronchoalveolar lavage fluid, and histological changes in the lung tissues. • We found the biomarkers of the oxidative stress, the pro-inflammatory cytokines and the apoptosis cytokine. • Vitamin E was found to be effective in reducing the toxicological effects. [ABSTRACT FROM AUTHOR]