UMBILICAL-CORD BLOOD LEAD LEVELS IN THE QUEBEC-CITY AREA

The purposes of this study were to determine the umbilical cord blood lead levels in a nonindustrialized city and the effect of place of res idence on the blood lead levels of newborns. During spring 1990, we co nducted a survey of umbilical cord blood lead levels from 823 live new borns in two hospitals from the Quebec City area. The geometric mean o f cord blood lead levels was 0.094 mumol/l (95% confidence interval [9 5% CI] = 0.088-0.099). Less than 1% (95% CI = 0.2-1.7) of the babies h ad cord blood lead levels at 0.48 mumol/l or greater. We estimate that each year in the Quebec City area between 150 and 200 newborns are at risk for developing psychoneurological problems during their first ye ars of life. Frequency distribution of cord blood lead level did not d iffer significantly among urban, suburban, and rural areas; however, a higher proportion of cord blood lead levels greater than 0.25 mumol/l was observed in the urban area (9.4%), compared with suburban (2.6%) and rural (3.1%) areas. The proximity of potential environmental lead sources (highway, industry, city center) located within 1/2 mile (.8 k m) of the mother's residence was associated with a high cord blood lea d level. Cord blood lead levels were also elevated for newborns whose mothers lived in newer (less-than-or-equal-to 5 y) and older buildings (greater-than-or-equal-to 50 y). We concluded that the environmental characteristics of the mother's residence are a better indicator of en vironmental lead exposure than the place of residence. Other factors d uring pregnancy (work, lifestyle, drinking water, diet) that play an i mportant role in the lead exposure of newborns could also partially ex plain our results.