Urban land-use and respiratory symptoms in infants

• Published in: Environmental research Vol. 111; no. 5; pp. 677 - 684
• Main Authors: Ebisu, Keita, Holford, Theodore R., Belanger, Kathleen D., Leaderer, Brian P., Bell, Michelle L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.07.2011; Elsevier
• Subjects: Air; Air pollution; Air Pollution - statistics & numerical data; asthma; Asthma - epidemiology; Biological and medical sciences; Buffers; children; Chronic obstructive pulmonary disease, asthma; Cities - statistics & numerical data; confidence interval; Connecticut; Connecticut - epidemiology; emissions; Environmental Exposure - analysis; Environmental Exposure - statistics & numerical data; Environmental pollutants toxicology; exposure models; Female; gender; Geographic Information Systems; Health; health services; Humans; Infant; Infant, Newborn; Infants; Infants' health; land cover; Land use; Male; Mathematical models; Medical sciences; Nitrogen dioxide; Nitrogen Dioxide - analysis; Odds Ratio; Particle Size; Particulate Matter - analysis; Pneumology; regression analysis; Respiratory Sounds; Risk; Social Class; socioeconomic status; Toxicology; Traffic; urban areas; Urbanicity; Wheeze symptom; United States; North America; America; Connecticut; USA, Connecticut; SES; OR; PM 2.5; Land-use; Traffic; SO 2; IQR; CO; Wheeze symptom; GIS; Infants' health; Urbanicity; U.S. EPA; NO 2; Human; Urban environment; Health; Infant; Wheezing; Urban area; Soil pollution; Respiratory system; Symptomatology; Air pollution; Public health
• ISSN: 0013-9351; 1096-0953; 1096-0953
• DOI: 10.1016/j.envres.2011.04.004

Children's respiratory health has been linked to many factors, including air pollution. The impacts of urban land-use on health are not fully understood, although these relationships are of key importance given the growing populations living in urban environments. We investigated whether the degree of urban land-use near a family's residence is associated with severity of respiratory symptoms like wheeze among infants. Wheeze occurrence was recorded for the first year of life for 680 infants in Connecticut for 1996–1998 from a cohort at risk for asthma development. Land-use categories were obtained from the National Land Cover Database. The fraction of urban land-use near each subject's home was related to severity of wheeze symptoms using ordered logistic regression, adjusting for individual-level data including smoking in the household, race, gender, and socio-economic status. Nitrogen dioxide (NO 2) exposure was estimated using integrated traffic exposure modeling. Different levels of urban land-use intensity were included in separate models to explore intensity-response relationships. A buffer distance was selected based on the log-likelihood value of models with buffers of 100–2000 m by 10 m increments. A 10% increase in urban land-use within the selected 1540 m buffer of each infant's residence was associated with 1.09-fold increased risk of wheeze severity (95% confidence interval, 1.02–1.16). Results were robust to alternate buffer sizes. When NO 2, representing traffic pollution, was added to the model, results for urban land-use were no longer statistically significant, but had similar central estimates. Higher urban intensity showed higher risk of prevalence and severity of wheeze symptoms. Urban land-use was associated with severity of wheeze symptoms in infants. Findings indicate that health effect estimates for urbanicity incorporate some effects of traffic-related emissions, but also involve other factors. These may include differences in housing characteristics or baseline healthcare status. ► We investigated whether urbanicity is associated with infant's respiratory health. ► We assessed urbanicity with satellite imagery and infant's health with cohort data. ► Urbanicity was associated with severity of wheeze symptoms in infants. ► Urbanicity captures several aspects of urban life, such as traffic-related emissions.