Traffic-related air pollution and spectacles use in schoolchildren

Abstract

PurposeTo investigate the association between exposure to traffic-related air pollution and use of spectacles (as a surrogate measure for myopia) in schoolchildren.MethodsWe analyzed the impact of exposure to NO2 and PM2.5 light absorbance at home (predicted by land-use regression models) and exposure to NO2 and black carbon (BC) at school (measured by monitoring campaigns) on the use of spectacles in a cohort of 2727 schoolchildren (7–10 years old) in Barcelona (2012–2015). We conducted cross-sectional analyses based on lifelong exposure to air pollution and prevalent cases of spectacles at baseline data collection campaign as well as longitudinal analyses based on incident cases of spectacles use and exposure to air pollution during the three-year period between the baseline and last data collection campaigns. Logistic regression models were developed to quantify the association between spectacles use and each of air pollutants adjusted for relevant covariates.ResultsAn interquartile range increase in exposure to NO2 and PM2.5 absorbance at home was respectively associated with odds ratios (95% confidence intervals (CIs)) for spectacles use of 1.16 (1.03, 1.29) and 1.13 (0.99, 1.28) in cross-sectional analyses and 1.15 (1.00, 1.33) and 1.23 (1.03, 1.46) in longitudinal analyses. Similarly, odds ratio (95% CIs) of spectacles use associated with an interquartile range increase in exposures to NO2 and black carbon at school was respectively 1.32 (1.09, 1.59) and 1.13 (0.97, 1.32) in cross-sectional analyses and 1.12 (0.84, 1.50) and 1.27 (1.03, 1.56) in longitudinal analyses. These findings were robust to a range of sensitivity analyses that we conducted.ConclusionWe observed increased risk of spectacles use associated with exposure to traffic-related air pollution. These findings require further confirmation by future studies applying more refined outcome measures such as quantified visual acuity and separating different types of refractive errors.

Refractive error, axial length, environmental and hereditary factors associated with myopia in Swedish children

“…Recent studies have shown that children living in urban areas with high population density and pollution are at higher risk of developing myopia. 1,42,43 Contrary to many cities in East Asia, the current sample was protected from these two factors because population density as well as pollution levels in Kalmar Län are low. 44 The pressure of education has also been linked to increased prevalence of myopia.…”

Effect of Genetic-Environmental Interaction on Chinese Childhood Myopia

“…A recent study had reported that myopia was associated with PM2.5 and NOx which could be an indicator of air pollution [ 29 ]. Exposure to air pollution had a weak link with development of myopia, and long-term studies should be implemented [ 30 ]. The outdoor light environment had been proved to play an important role in the onset and progression of myopia [ 31 ], but data concerning indoor light environment were limited.…”

Risk Factors for Myopia: Putting Causal Pathways into a Social Context

“…Speculation about this factor has been fueled by the high levels of air pollution seem in some parts of China, but in fact, in international terms, Chinese cities rank well behind many cities in South Asia and the Middle East, where the prevalence of myopia is much lower than in Chinese cities (https://www.who.int/airpollution/ data/cities/en/, accessed Jan 30, 2019). Increased use of spectacles, presumably for myopia, has been associated with traffic-related pollution [154], but this may in fact be related to the association between urban residence and more myopia, as well as links to socioeconomic status, area of residence, and education [153].…”