Lead exposure and birth outcomes in five communities in Shoshone County, Idaho.
BACKGROUND
This study examined birth outcomes in five towns in Shoshone County, Idaho, where residents were exposed to high levels of lead in air emissions during a 6-month period after a fire had damaged the main baghouse (pollution-control device) of a local lead smelter plant in September 1973.


METHODS
We studied birth certificate data of 169,878 live singleton infants born to mothers who resided in Idaho at the time of delivery. The outcomes evaluated were preterm infants, small-for-gestational-age (SGA) infants, low birthweight among term infants (TLBW), and mean birthweight among term infants (TMBW). The study compared births in the five towns in Shoshone County (exposed group) to births in the rest of Idaho during three exposure periods: "pre-fire," January 1, 1970-August 31, 1973; "high exposure," September 1, 1973-December 31, 1974; and "post-fire," January 1, 1975-December 31, 1981.


RESULTS
During the high-exposure period, the exposed group had an increased prevalence of TLBW (OR=2.4; 90% CI: 1.6-3.6) and SGA (OR=1.9; 90% CI: 1.3-2.8) compared with the rest of Idaho. During the pre- and post-fire periods, the ORs for TLBW were 0.8 and 1.3, respectively, and for SGA, 1.0, and 1.3, respectively. During the high-exposure period, TMBW for the exposed group was 71 g lower than in the comparison group. The TMBW in the exposed group was 8 g lower in the pre-fire period and 26 g lower in the post-fire period than in the comparison group. The study found no increased risk for preterm birth in the exposed group.


CONCLUSIONS
Maternal exposures to airborne lead emissions appeared to be associated with increased risks for SGA, TLBW, and reduced TMBW.
Berkowitz
Zahava
Z
Agency for Toxic Substances and Disease Registry, Division of Health Studies, Epidemiology and Surveillance Branch, 1600 Clifton Road, MS E-31, Atlanta, GA 30333, USA. zab3@cdc.gov
Price-Green
Patricia
P
Bove
Frank J
FJ
Kaye
Wendy E
WE
D005260:Female; D006801:Humans; D007061:Idaho / Q000453:epidemiology; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D007854:Lead / Q000633:toxicity*; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D015997:Neonatal Screening / Q000379:methods; D016017:Odds Ratio; D047928:Premature Birth / Q000453:epidemiology*; D015995:Prevalence; D012044:Regression Analysis
D007854:Lead