Air pollution study confirms concerns over childhood rickets

A study in India has shown that young children living in areas of high air pollution are in danger of developing rickets.

Two groups of age matched infants and toddlers were compared for serum vitamin D metabolites, calcium, alkaline phosphatase (AP), and parathormone (PTH) concentrations. One group lived in a central location in Delhi and the other on the outskirts of the city, where air pollution is much lower.

Children from the city centre had significantly lower mean serum total 25-hydroxyvitamin D (25(OH)D)—an indictor of vitamin D status—than children from the outskirts (12.4 ng/ml v 27.1 ng/ml). Their mean serum AP and PTH concentrations were significantly higher, and the inverse relations between 25(OH)D and AP, PTH were also significant. Three children had serum total 25(OH)D low enough to indicate rickets, and nine more below adequate amounts. All children from the outskirts had adequate 25(OH)D. Mean haze score was significantly less at the city centre (2.1 against 2.7).

Each group included 34 children aged 9–24 months with similar home conditions, diet, family income, and time spent outside. Blood was taken from 26 children from the city centre and 31 from the outskirts. Haze scores measured at ground level three times daily (0900, 1200, 1600) during February 2000 were taken as a marker for UVB radiation.

Concerns are growing that increasing air pollution from industry and motor vehicles blocks out UVB radiation and children's ability to make vitamin D naturally, leading to rickets.