Blood lead levels of both mothers and their newborn infants in the middle part of China

Abstract

A cross-sectional investigation on maternal and umbilical blood lead levels in an urban area, an industrial town and a rural area of middle China is reported. Blood samples from 89 mothers during delivery, from the umbilical cords and from 105 non-pregnant women were collected. Self-administered questionnaires including the medical history and the pregnancy-related complaints were performed. After acid digestion, the whole blood lead levels were determined by a 180-80 flame atomic absorption spectrometer. The geometric mean for lead levels in blood of non-pregnant women was 66.9 microg/l (range: 25.0-201.0 microg/l) in the urban, 66.9 microg/l (range: 30.5-198.8 microg/l) in the industrial town, and 53.3 microg/l (range: 16.0-170.5 microg/l) in the rural area. The geometric mean of lead levels in blood of pregnant women at delivery both in the rural area (74.4 microg/l, range: 35.2-245.6 microg/l) and industrial town (65.9 micro/l, range: 20.0-172.0 microg/l) were higher than in the urban region (54.3 microg/l, range: 27.9-187.0 microg/l; p < 0.05). Compared with non-pregnant women at the same area, the blood lead levels of pregnant women was lower in urban (p < 0.05), but higher in rural areas (p < 0.05). The geometric mean for lead level in umbilical cord blood was significantly higher in rural (84.1 microg/l, range: 28.0-185.0 microg/l) than in the other areas (53.5 microg/l, range: 23.5-156.7 microg/l in the urban; 60.1 microg/l, range: 12.5-168.3 microg/l in the industrial town). The total geometric mean for lead level in cord blood was 69.0 microg/l (range: 12.5-185.0 microg/l), and 17.8% samples were above the blood lead threshold of health concern (> or =100 microg/l) for children (CDC, 1991), but the body weight and length of newborn babies have not been affected. The correlation between maternal and cord blood was 0.6805 (p < 0.01). Most of the pregnant women did not take the calcium supplements recommended during pregnancy. In conclusion, there were some lead burdens on both the mothers and their newborn babies in these areas. All possible measures should be taken to reduce the environmental lead exposure. It is also crucial that maternal nutrient intake, particularly calcium, should be sufficient.