Abstract:
Air pollution is a major concern in urban areas of developing countries as a result of industrial
expansion and increased vehicular ownership, and in most households due to solid fuel use and
garbage burning at home. Urban poverty is also widespread in developing countries, and besides
perpetuating household air pollution (HAP), it has also meant hazardous occupational choices
such as street vending by the urban poor. The epidemiologic evidence linking HAP exposure with
adverse pregnancy outcomes is very limited. Research on the health effects of street vending is
also scarce with its relationship with fetal growth still unexplored in spite of women dominating
this venture.
This project assessed the effects of HAP practices and ambient air pollution exposure on fetal
growth and gestational duration, and elaborated the role of environmental exposures in the
influence of socioeconomic deprivation on pregnancy endpoints. The project comprised an
epidemiologic study, and a qualitative and quantitative synthesis of evidence.
A cross-sectional study of 1,151 mothers-infant pairs accessing postnatal services at the Korle
Bu Teaching Hospital in Accra (n = 592), and the four main health facilities in Cape Coast (n =
559) was conducted. Information on socioeconomic characteristics and activity patterns of
mothers, and characteristics of the indoor and outdoor environment were collected in a structured
questionnaire. Birth weight and gestational age was retrieved from hospital records. PUBMED,
Ovid MEDLINE, SCOPUS and CINAHL databases were searched for studies investigating HAP
exposure and pregnancy outcomes for the review.
Multivariate modeling adjusting for confounders resulted in a 243g (95% CI: 496, 11)
reduction in birth weight and 41% (risk ratio [RR] = 1.41; 95% CI: 0.62, 3.23) increased risk of
low birth weight (LBW) for use of charcoal. Garbage burning was associated with a 195% (RR =
2.95; 95% CI: 1.10, 7.92) increased risk of LBW. The meta-analysis indicated an 86.43g (95% CI:
55.49, 117.37) reduction in birth weight and a 35% (summary-effect estimate [EE] = 1.35; 95%
CI: 1.23, 1.48) increased risk of LBW for solid fuel use. Increased risk of other pregnancy
endpoints with use of solid fuels was also noted in the meta-analysis. Moderate street vending
activity and high traffic density in the vending area jointly resulted in 84% (RR = 1.84; 95% CI:
1.05, 3.24) and 29% (RR = 1.29; 95% CI: 0.68, 2.46) increased risk of LBW and preterm birth,
respectively. Evidence of the effects of maternal socioeconomic disadvantage on pregnancy
outcomes was noted, with HAP especially substantially mediating the observed effects.
Interventions for mitigating the effects of solid fuel use on health call for eliminating barriers
to the adoption of cleaner fuels and educating women about behavioral changes required to
minimize exposure. Government should also extend their social safety net programs to pregnant
women engaged in hazardous occupations to enable them give up or minimize the number of hours
in the work.
