BACKGROUND: Recent evidence implicates fine particulate matter (PM2.5), principally from vehicular exhaust, as a major cause of increased mortality and morbidity. However, there are limited data on the impact of PM2.5 on infant respiratory illnesses. METHODS: We conducted a cohort study of 504 infants recruited at 4 months of age from primary health care units in southeastern Santiago, Chile. Project physicians followed infants through the first year of life via monthly check-ups and by appointments on demand. We obtained data for fine particulate matter, sulfur dioxide (SO2), and nitrogen dioxide (NO2) from the governmental monitoring network. RESULTS: The most frequent diagnosis during follow-up was wheezing bronchitis, occurring 19.5 times per 100 infants per month. After adjusting for sex, socioeconomic level, family history of asthma, minimum temperature, and number of older siblings, we found that an increase of 10 microg/m of PM2.5 24-hour average was related to a 5% increase (95% confidence interval 0-9%) in the risk for wheezing bronchitis (1-day lag). This association was present for different lags, with a maximum observed for a 9-day lag (9%; 6-12%). No consistent association was detected with NO2 or SO2 ambient levels. Lower socioeconomic status and having older siblings were also associated with the risk of wheezing bronchitis. The association of PM2.5 and wheezing bronchitis was stronger among infants with a family history of asthma than among infants without. CONCLUSIONS: Air pollution in the form of fine particulates, mostly from vehicular exhaust, may adversely affect infants' respiratory health with potential for chronic effects later in life.
BACKGROUND: Recent evidence implicates fine particulate matter (PM2.5), principally from vehicular exhaust, as a major cause of increased mortality and morbidity. However, there are limited data on the impact of PM2.5 on infant respiratory illnesses. METHODS: We conducted a cohort study of 504 infants recruited at 4 months of age from primary health care units in southeastern Santiago, Chile. Project physicians followed infants through the first year of life via monthly check-ups and by appointments on demand. We obtained data for fine particulate matter, sulfur dioxide (SO2), and nitrogen dioxide (NO2) from the governmental monitoring network. RESULTS: The most frequent diagnosis during follow-up was wheezing bronchitis, occurring 19.5 times per 100 infants per month. After adjusting for sex, socioeconomic level, family history of asthma, minimum temperature, and number of older siblings, we found that an increase of 10 microg/m of PM2.5 24-hour average was related to a 5% increase (95% confidence interval 0-9%) in the risk for wheezing bronchitis (1-day lag). This association was present for different lags, with a maximum observed for a 9-day lag (9%; 6-12%). No consistent association was detected with NO2 or SO2 ambient levels. Lower socioeconomic status and having older siblings were also associated with the risk of wheezing bronchitis. The association of PM2.5 and wheezing bronchitis was stronger among infants with a family history of asthma than among infants without. CONCLUSIONS: Air pollution in the form of fine particulates, mostly from vehicular exhaust, may adversely affect infants' respiratory health with potential for chronic effects later in life.
Authors: Z Wang; S L Shalat; K Black; P J Lioy; A A Stambler; O H Emoekpere; M Hernandez; T Han; M Ramagopal; G Mainelis Journal: Indoor Air Date: 2011-10-24 Impact factor: 5.770
Authors: Stuart L Shalat; Adam A Stambler; Zuocheng Wang; Gediminas Mainelis; Osiloke H Emoekpere; Marta Hernandez; Paul J Lioy; Kathleen Black Journal: Environ Sci Technol Date: 2011-02-25 Impact factor: 9.028
Authors: Jennifer L Peel; Mitchel Klein; W Dana Flanders; James A Mulholland; Gary Freed; Paige E Tolbert Journal: Environ Health Perspect Date: 2011-03-29 Impact factor: 9.031
Authors: Janneane F Gent; Petros Koutrakis; Kathleen Belanger; Elizabeth Triche; Theodore R Holford; Michael B Bracken; Brian P Leaderer Journal: Environ Health Perspect Date: 2009-03-31 Impact factor: 9.031