Benefits of Reducing Prenatal Exposure to Coal-Burning Pollutants to Children’s Neurodevelopment in China

Abstract

BackgroundCoal burning provides 70% of the energy for China’s industry and power, but releases large quantities of polycyclic aromatic hydrocarbons (PAHs) and other pollutants. PAHs are reproductive and developmental toxicants, mutagens, and carcinogens.ObjectiveWe evaluated the benefit to neurobehavioral development from the closure of a coal-fired power plant that was the major local source of ambient PAHs.MethodsThe research was conducted in Tongliang, Chongqing, China, where a coal-fired power plant operated seasonally before it was shut down in May 2004. Two identical prospective cohort studies enrolled nonsmoking women and their newborns in 2002 (before shutdown) and 2005 (after shutdown). Prenatal PAH exposure was measured by PAH–DNA adducts (benzo[a]pyrene–DNA) in umbilical cord blood. Child development was assessed by the Gesell Developmental Schedules at 2 years of age. Prenatal exposure to other neurotoxicants and potential confounders (including lead, mercury, and environmental tobacco smoke) was measured. We compared the cohorts regarding the association between PAH–DNA adduct levels and neurodevelopmental outcomes.ResultsSignificant associations previously seen in 2002 between elevated adducts and decreased motor area developmental quotient (DQ) (p = 0.043) and average DQ (p = 0.047) were not observed in the 2005 cohort (p = 0.546 and p = 0.146). However, the direction of the relationship did not change.ConclusionThe findings indicate that neurobehavioral development in Tongliang children benefited by elimination of PAH exposure from the coal-burning plant, consistent with the significant reduction in PAH–DNA adducts in cord blood of children in the 2005 cohort. The results have implications for children’s environmental health in China and elsewhere.

Exposure to widespread environmental toxicants and children’s cognitive development and behavioral problems

“…The next study performed in the same region of China in 2005 (after shutdown of the power plant) examined the exposure to PAHs and neurobehavioral development in children at 2 years of age [27]. Significant associations previously seen in 2002 [26] were not observed in the 2005 cohort [27]. The results of the presented studies provide evidence that environmental PAH exposure may adversely affect children's neurodevelopment [22,23,25].…”

“…Increased PAH-DNA adduct levels were associated with decreased developmental quotients in motor area (p = 0.043), and average (p = 0.047) [26]. The next study performed in the same region of China in 2005 (after shutdown of the power plant) examined the exposure to PAHs and neurobehavioral development in children at 2 years of age [27]. Significant associations previously seen in 2002 [26] were not observed in the 2005 cohort [27].…”

“…PAHs have been shown to be neurodevelopmental toxicants in experimental studies [19][20][21]. There are 8 human epidemiological studies which have examined an association between exposure to PAHs and children's development [22][23][24][25][26][27], one study has investigated how polymorphism in PAH metabolic genes affects child cognitive development [28], and another one has assessed the combined exposure to environmental tobacco smoke (ETS) and PAH-DNA adducts after the World Trade Center catastrophe and its impact on child development [29] (Table 4).…”

“…One study indicated that Mental Development Index at young ages can be modulated by common genetic variants in the key genes CYP1A1, CYP1A2, CYP1B1, GSTT2, and GSTM1 [28]. In the studies in China enrolling nonsmoking women and their newborns in 2002 (before power plant was shutdown) and 2005 (after power plant was shutdown) the authors noticed that significant associations previo usly seen in 2002 between elevated adducts and decreased motor function were not observed in the 2005 cohort what was associated with the reduction of the PAH exposure [26,27].…”

Memory and fine motor skill test performance among children living near coal ash storage sites.

“…Two prospective cohort studies explored the effects of prenatal exposure to coal-burning pollutants on children's development in Tongliang, Chongqing, China Perera et al, 2008;Tang et al, 2014). The first prospective cohort began while the power plant was still in operation .…”