Association of Black Carbon with Cognition among Children in a Prospective Birth Cohort Study

Abstract

While studies show that ultrafine and fine particles can be translocated from the lungs to the central nervous system, the possible neurodegenerative effect of air pollution remains largely unexplored. The authors examined the relation between black carbon, a marker for traffic particles, and cognition among 202 Boston, Massachusetts, children (mean age = 9.7 years (standard deviation, 1.7)) in a prospective birth cohort study (1986-2001). Local black carbon levels were estimated using a validated spatiotemporal land-use regression model (mean predicted annual black carbon level, 0.56 mug/m(3) (standard deviation, 0.13)). The Wide Range Assessment of Memory and Learning and the Kaufman Brief Intelligence Test were administered for assessment of cognitive constructs. In analysis adjusting for sociodemographic factors, birth weight, blood lead level, and tobacco smoke exposure, black carbon (per interquartile-range increase) was associated with decreases in the vocabulary (-2.2, 95% confidence interval (CI): -5.5, 1.1), matrices (-4.0, 95% CI: -7.6, -0.5), and composite intelligence quotient (-3.4, 95% CI: -6.6, -0.3) scores of the Kaufman Brief Intelligence Test and with decreases on the visual subscale (-5.4, 95% CI: -8.9, -1.9) and general index (-3.9, 95% CI: -7.5, -0.3) of the Wide Range Assessment of Memory and Learning. Higher levels of black carbon predicted decreased cognitive function across assessments of verbal and nonverbal intelligence and memory constructs.

Impact of Air Pollution on Public Health

“…Children, whose mothers were exposed to high concentrations of PM during pregnancy, more often were born with low birth weight and 10 µg/m 3 change in PM 10 accounted for 13.7 g less of weight [59,60,61]. Effect of mothers' exposure to high concentration (above the median 36.3 µg/m 3 ) of fine particles (PM 2,5 ) was reflected in significantly lower mean weight (128.3g) and length (0.9cm) and lower mean head circumference (0.3) of newborns [62]. The researchers in the USA found that mothers who lived in areas with the highest levels of PM 2.5 during their pregnancy delivered slightly smaller babies than their counterparts who lived in areas with lower levels of PM 2.5 exposure.…”

“…The effects were roughly equivalent to those seen in children whose mothers smoked ten cigarettes per day while pregnant. The researchers assumed that the harmful effects may be caused by the inflammatory and oxidative effects of the black carbon particles [5]. These findings suggest additional research is needed to investigate the effects of air pollution on the development of intelligence in children and on cognitive decline for people of all ages.…”

Disruption of Neurosynaptic Physiology and Neuron Network Dysfunction in Brain Disorders: An Environmental and Occupational Health Perspective

“…Polycyclic aromatic hydrocarbon exposure of pregnant mothers resulted in babies having lower IQs at 5 year than unexposed peers [174]. Black carbon exposure caused downgrading of IQs in babies at 9 year age [175]. Significant reduction in psychomotor, attention and sensory scales, without cognitive impairment was observed in children studying at school located in area of dense city traffick, compared to those from clean air area [176].…”

Seasonal Variation of Mass Absorption Efficiency of Elemental Carbon in the Four Major Emission Areas in China

“…Light-absorbing carbon (LAC) is getting much more attentions from researchers and policy-makers for its considerable effect on global and regional climate change (Chung and Seinfeld, 2005;Ramanathan and Carmichael, 2008), air quality and human health (Jansen et al, 2005;Suglia et al, 2008), and its reduction has been targeted for near-term global warming mitigation (Shindell et al, 2012). Black carbon (BC) defined optically is a useful qualitative description when referring to light absorbing carbon in atmospheric aerosols .…”