Gestational Exposure to PM2.5 and Specific Constituents, Meconium Metabolites, and Neonatal Neurobehavioral Development: A Cohort Study.

Exposure to fine particulate matter (PM2.5) during pregnancy has been inversely associated with neonatal neurological development. However, the associations of exposure to specific PM2.5 constituents with neonatal neurological development remain unclear. We investigated these associations and examined the mediating role of meconium metabolites in a Chinese birth cohort consisting of 294 mother-infant pairs. Our results revealed that exposure to PM2.5 and its specific constituents (i.e., organic matter, black carbon, sulfate, nitrate, and ammonium) in the second trimester, but not in the first or third trimester, was inversely associated with the total neonatal behavioral neurological assessment (NBNA) scores. The PM2.5 constituent mixture in the second trimester was also inversely associated with NBNA scores, and sulfate was identified as the largest contributor. Furthermore, meconium metabolome analysis identified four metabolites, namely, threonine, lysine, leucine, and saccharopine, that were associated with both PM2.5 constituents and NBNA scores. Threonine was identified as an important mediator, accounting for a considerable proportion (14.53-15.33%) of the observed inverse associations. Our findings suggest that maternal exposure to PM2.5 and specific constituents may adversely affect neonatal behavioral development, in which meconium metabolites may play a mediating role.

The mobile monitoring of black carbon and its association with roadside data in the Chinese megacity of Shanghai.

High-level black carbon (BC) pollution is associated with traffic emissions in metropolitan areas with high vehicle density. Mobile monitoring was conducted to assess the in-vehicle BC exposure on three backbone ring roads (inner, middle, and outer ring roads) on October 14 and October 18, 2015 in Shanghai. Ambient BC monitoring was also simultaneously conducted in three fixed roadside stations from October 14 to October 20, 2015. Results of the mobile monitoring showed median BC personal exposure concentrations ranging from 5.0 µg m-3 on the inner ring road to 13.5 µg m-3 on the outer ring road. The ambient BC concentrations during the entire observation period showed an arithmetic mean and a standard deviation of 3.5 ± 2.9 µg m-3. The correlation analysis of urban roadside monitoring (Caoxi Road and South Zhongshan Road) and personal data showed a high and significant correlation. The results of this study highlight the critical level of BC pollution in Shanghai and facilitate the development of evidence-based public health interventions and control strategies to prevent the adverse health effects of BC pollution.

Personal exposure to black carbon during commuting in peak and off-peak hours in Shanghai.

A study on a commuter's exposure to black carbon (BC) in five different traffic modes (taxi, bus, subway, cycling and walking) was conducted in Xuhui District, Shanghai. A commuter's real-time exposure concentrations were recorded by MicroAeth AE51 BC monitors, and the average BC exposure concentration and inhalation dose were analyzed. Data collected by cyclist was applied to characterize the micro-variability in relation to traffic density and street topology. The distance to the traffic and the street topology as well as the volume of heavy diesel trucks were the dominant factors influencing the BC concentrations. In this study, a high variability of BC concentrations between streets and even within streets was observed, and also between days and hour of the day. The average BC exposure concentrations were 5.59±1.02 µg/m(3), 6.58±1.78 µg/m(3), 7.28±1.87 µg/m(3), 8.62±4.13 µg/m(3) and 9.43±2.89 µg/m(3) for walking, cycling, bus, taxi and subway trips, respectively. Exposure levels of in-vehicle microenvironments were 8.66±3.66 µg/m(3), 9.39±6.98 µg/m(3) and 10.96±2.72 µg/m(3) for bus, taxi and subway, respectively. While inhalation doses were 0.68±0.33 µg, 0.95±0.29 µg, 1.36±0.37 µg, 1.50±0.39 µg and 1.58±0.29 µg for taxi, subway, cycling, bus and walking, respectively. BC exposure level of walking was the lowest among all the traffic modes, but its inhalation dose was the highest.