Table 6

Wood burning and ALRI in children under five in developed countries

Study Design Case definition Exposure Confounding adjusted Comments OR (95% CI)
Navaho reservation (1988) Tuba City, Arizona, USA (Morriset al)69 Case-control 0–24 months n=58+58 Hospital:
Cases: ALRI, bronchiolitis, pneumonia clinical and x ray
Controls: Age-sex matched, well child clinic
Interview:
Primary energy source for heating and cooking
Family history of asthma, recent exposure to respiratory disease, dirt floor, presence of running water.Wood burning stoves with chimneys but exposure levels not validated. Recent exposure to respiratory disease only other factor remaining significant (OR 1.4) after multivariate analysis. Humidifiers, ETS, pets, crowding, and house type not significant.4.8 (1.7 to 12.9)
Navaho reservation (1993) Fort Defiance, Arizona, USA (Robinet al)70 Case-control 1–24 months n=45+45Hospital:
Cases: ALRI, bronchiolitis, pneumonia
Controls: Age-sex matched, sought care not for other conditions
Interview: cook with wood
Measured 15 h PM10 levels (5 pm–8 am)
Interview
• children/hh
• running water
• electricity
• difficulty of transport to clinic
• ETS
• house type
No variation in PM10levels with ETS, type of home, etc. Type of cooking/heating only explained 10% of variance. Median PM10 levels 24 μg/m3 (cases), 22 μg/m3 (controls). No effect for coal use or wood for heating, but sample sizes smallCook with wood 5.0 (0.6 to 43)
PM >65 μg/m3 7.0 (0.9 to 57)
  • As in table 5, this list is confined to those quantitative studies using standardised protocols for determining ALRI. Other studies have just looked at the relationship of wood burning with respiratory symptoms, e.g. Honicky et al,71 Butterfield et al,72 and Browning et al 73 which are discussed in the text.