Reductions in blood lead levels among school children following the introduction of unleaded petrol in South Africa

Epidemiological studies have indicated that in the 1980s and early 1990s (a period in which petrol lead concentrations in South Africa ranged from 0.836 to 0.4 g/L), large proportions of urban South African children were at risk of excessive exposure to environmental lead. In 1991, when the maximum permissible petrol lead concentration in the country equaled 0.4 g/L, a study determined that the mean blood lead level among children attending inner city schools in the Cape Peninsula equaled 16 microg/dL, with well over 90% of children having blood lead levels equaling or exceeding the internationally accepted guideline level of 10 microg/dL. Socio economic status, housing conditions, and proximity of children's schools and homes to heavily trafficked roads were among the factors significantly associated with blood lead concentrations. In 1996, unleaded petrol was introduced in South Africa. A study undertaken in 2002 (at the same schools as in 1991), when unleaded petrol constituted around 30% of the market share of petrol in the country, has shown significant reductions in the mean blood lead concentration among Cape Peninsula inner city children and in the proportion of children with elevated blood lead levels. The mean blood lead level for the total sample (n = 429) of children whose mean age equaled 7 years (range: 5-11 years) was 6.4 microg/dL (range: 1.0-24.5 microg/dL) and 10% of children had blood lead levels equalling or exceeding 10 microg/dL. The mean blood lead levels among children attending schools in an inner city and in a less heavily trafficked periurban suburb were 6.9 and 4.8 microg/dL, respectively.     

A survey of blood lead levels among young Johannesburg school children

Studies conducted around the world have established beyond doubt that elevated childhood blood lead levels may lead to detrimental health effects. Research has shown that certain groups of South African children are at particular risk of elevated blood lead levels. Johannesburg is the largest urban complex in southern Africa, with a population of around 3 million and extensive industrial and manufacturing activity. Among the challenges posed in the city are rapid urbanization, extensive poverty, and inequity. Little information on the blood lead distribution of Johannesburg children is available.This study was undertaken to determine blood lead levels among children living in three areas of Johannesburg: inner city suburbs and the low-income townships of Alexandra and Westbury to the north and west of the city center, respectively.The results indicated that blood lead levels ranged from 6 to 26 micro g/dL, with a mean level of 11.9 micro g /dL. The blood lead levels of 78% of children equaled or exceeded 10 micro g/dL, the current international action level. Maternal educational status, the presence of smokers in the home, and living in an informal dwelling were among the factors associated with elevated blood lead levels.     

Blood lead levels among children of lead-exposed workers: A meta-analysis.

BACKGROUND: To further assess the utility of targeted blood lead screening for children from households with members having occupational lead exposures, we conducted a meta-analysis of all available reports of take-home lead exposures. Our objective was to estimate the blood lead levels among U.S. children (ages 1-5) from households with lead-exposed workers. METHODS: Reports considered for inclusion were cited in Medline, Toxline, Excerpta Medica, and Bio-Med plus all unpublished reports available at the National Institute for Occupational Safety and Health through 1994. The a priori criteria for inclusion of U.S. reports required their having data on: (1) venous blood lead levels for children, (2) children's ages, (3) data for at least five children, (4) workers' occupations, (5) workers' blood lead levels, and (6) data collection methods. RESULTS: Based on a meta-analysis of 10 reports from 1987 through 1994, the children (n=139) of lead-exposed workers (n=222) had a geometric mean blood lead level of 9.3 microg/dL compared to a U.S. population geometric mean of 3.6 microg/dL (P=0.0006). Also in this group, 52% of the children had blood lead levels (BLLs) >/= 10 microg/dL compared to 8.9% in the U.S. (P=.0010), and 21% of the children had BLLs >/= 20 microg/dL compared to 1.1% in the U.S. (P=. 0258). CONCLUSIONS: We estimate, based on 1981-83 survey data, that there are about 48,000 families with children under six living with household members occupationally exposed to lead. If the findings from this meta-analysis (admittedly limited by small numbers) are generalizable, about half of the young children in these families may have BLLs >/= 10 microg/dL. Data were too sparse to determine if children of workers with elevated blood leads were at greater risk than children whose parents were only known to be lead exposed. Our findings support the position that children of lead-exposed workers should be targeted for blood lead screening. Am. J. Ind. Med. 36:475-481, 1999. Published 1999 Wiley-Liss, Inc.     

Iron deficiency associated with higher blood lead in children living in contaminated environments.

The evidence that iron deficiency increases lead child exposure is based primarily on animal data and limited human studies, and some of this evidence is contradictory. No studies of iron status and blood lead levels in children have accounted for environmental lead contamination and, therefore, the source of their exposure. Thus, no studies have directly determined whether iron deficiency modifies the relationship of environmental lead and blood lead. In this study, we compared blood lead levels of iron-deficient and iron-replete children living in low, medium, or highly contaminated environments. Measurements of lead in paint, soil, dust, and blood, age of housing, and iron status were collected from 319 children ages 1-5. We developed two lead exposure factors to summarize the correlated exposure variables: Factor 1 summarized all environmental measures, and Factor 2 was weighted for lead loading of house dust. The geometric mean blood lead level was 4.9 microg/dL; 14% exceeded 10 microg/dL. Many of the children were iron deficient (24% with ferritin < 12 ng/dL). Seventeen percent of soil leads exceeded 500 microg/g, and 23% and 63% of interior and exterior paint samples exceeded 5,000 microg/g. The unadjusted geometric mean blood lead level for iron-deficient children was higher by 1 microg/dL; this difference was greater (1.8 microg/dL) after excluding Asians. Blood lead levels were higher for iron-deficient children for each tertile of exposure as estimated by Factors 1 and 2 for non-Asian children. Elevated blood lead among iron-deficient children persisted after adjusting for potential confounders by multivariate regression; the largest difference in blood lead levels between iron-deficient and -replete children, approximately 3 microg/dL, was among those living in the most contaminated environments. Asian children had a paradoxical association of sufficient iron status and higher blood lead level, which warrants further investigation. Improving iron status, along with reducing exposures, may help reduce blood lead levels among most children, especially those living in the most contaminated environments.     

Low-level environmental lead exposure and children's intellectual function: an international pooled analysis

Lead is a confirmed neurotoxin, but questions remain about lead-associated intellectual deficits at blood lead levels < 10 microg/dL and whether lower exposures are, for a given change in exposure, associated with greater deficits. The objective of this study was to examine the association of intelligence test scores and blood lead concentration, especially for children who had maximal measured blood lead levels < 10 microg/dL. We examined data collected from 1,333 children who participated in seven international population-based longitudinal cohort studies, followed from birth or infancy until 5-10 years of age. The full-scale IQ score was the primary outcome measure. The geometric mean blood lead concentration of the children peaked at 17.8 microg/dL and declined to 9.4 microg/dL by 5-7 years of age; 244 (18%) children had a maximal blood lead concentration < 10 microg/dL, and 103 (8%) had a maximal blood lead concentration < 7.5 microg/dL. After adjustment for covariates, we found an inverse relationship between blood lead concentration and IQ score. Using a log-linear model, we found a 6.9 IQ point decrement [95% confidence interval (CI), 4.2-9.4] associated with an increase in concurrent blood lead levels from 2.4 to 30 microg/dL. The estimated IQ point decrements associated with an increase in blood lead from 2.4 to 10 microg/dL, 10 to 20 microg/dL, and 20 to 30 microg/dL were 3.9 (95% CI, 2.4-5.3), 1.9 (95% CI, 1.2-2.6), and 1.1 (95% CI, 0.7-1.5), respectively. For a given increase in blood lead, the lead-associated intellectual decrement for children with a maximal blood lead level < 7.5 microg/dL was significantly greater than that observed for those with a maximal blood lead level > or = 7.5 microg/dL (p = 0.015). We conclude that environmental lead exposure in children who have maximal blood lead levels < 7.5 microg/dL is associated with intellectual deficits.     

Lead exposure among females of childbearing age--United States, 2004

For centuries, exposure to high concentrations of lead has been known to pose health hazards, and evidence is mounting regarding adverse health effects from moderate- and low-level blood lead concentrations. Public health authorities use higher levels to define blood lead levels (BLLs) of concern in nonpregnant females (> or =25 microg/dL) compared with children (> or =10 microg/dL) and a lower level (> or =5 microg/dL) for pregnant females. This difference in levels for nonpregnant and pregnant females has raised concern because of the recognition that a proportion of nonpregnant females with BLLs > or =5 microg/dL will become pregnant and potentially expose their infants to a risk for adverse health effects from lead. Maternal and fetal BLLs are nearly identical because lead crosses the placenta unencumbered. This report summarizes 2004 surveillance data regarding elevated BLLs among females of childbearing age (i.e., aged 16-44 years) in 37 states participating in CDC's Adult Blood Lead Epidemiology and Surveillance (ABLES) program. The results indicated that rates of elevated BLLs ranged from 0.06 per 100,000 females of childbearing age at BLLs of > or =40 microg/dL to 10.9 per 100,000 females at BLLs of > or =5 microg/dL. Primary and secondary prevention of lead exposure among females of childbearing age is needed to avert neurobehavioral and cognitive deficits in their offspring.     

Demographic and socioeconomic factors associated with blood lead levels among Mexican-American children and adolescents in the United States

OBJECTIVE: This study was designed to assess demographic and socioeconomic differences in blood lead levels (BLLs) among Mexican-American children and adolescents in the United States. METHODS: We analyzed data from the Third National Health and Nutrition Examination Survey, 1988-1994, for 3,325 Mexican-American youth aged 1 to 17 years. The main study outcome measures included a continuous measure (microg/dL) of BLL and two dichotomous measures of BLL (> or =5 microg/dL and > or =10 microg/dL). RESULTS: The mean BLL among Mexican-American children in the United States was 3.45 microg/dL (95% confidence interval [CI] 3.07, 3.87); 20% had BLL > or =5 microg/dL (95% CI 15%, 24%); and 4% had BLL > or =10 microg/dL (95% CI 2%, 6%). In multivariate analyses, gender, age, generational status, home language, family income, education of head of household, age of housing, and source of drinking water were statistically significant independent predictors (p<0.05) of having higher BLLs and of having BLL > or =5 microg/dL, whereas age, family income, housing age, and source of drinking water were significant predictors (p<0.05) of having BLL > or =10 microg/dL. CONCLUSIONS: Significant differences in the risk of having elevated BLLs exist among Mexican-American youth. Those at greatest risk should be prioritized for lead screening and lead exposure abatement interventions.     

Lead poisoning among young children in Russia: concurrent evaluation of childhood lead exposure in Ekaterinburg,Krasnouralsk, and Volgograd

The Gore-Chernomyrdin Commission encouraged a binational collaboration to evaluate pediatric lead poisoning in Russia. The study evaluated children in three Russian cities: Krasnouralsk, a small city with minimal traffic centered around a copper smelter; and Ekaterinburg and Volgograd, both of which are large cities with multiple factories and heavy vehicular traffic. This project was the first international use of portable blood lead analysis instruments. In each city, at least 90% of children attending selected neighborhood kindergartens participated. We selected kindergartens on the basis of their proximity to industrial areas and major traffic corridors. We obtained capillary blood samples and analyzed for lead content and hemoglobin (Hgb) levels in the field, and collected environmental samples (i.e., indoor dust, tap water, play area soil, and interior and exterior paint) and analyzed for each participating school and in the homes of about 10% of the children who had elevated blood lead levels (BLLs; greater than or equal to 10 microg/dL). We calculated all age-, sex-, and city-specific geometric means using generalized estimating equations to account for covariance within kindergartens, and used multivariate logistic regression models to identify variables predictive of elevated BLLs. Overall, 23% of study children had elevated BLLs and 2% were anemic, defined as Hgb < 11 g/dL. Krasnouralsk had the highest geometric mean BLL (10.7 microg/dL), the highest percentage of children (60%) with elevated BLLs, and the highest percentage of anemic children (4%). All soil samples in Krasnouralsk had detectable lead levels. Volgograd was the only city that had paint samples with elevated lead levels. We found apparent city-specific differences in the percentages of children with elevated BLLs. Lead-contaminated soil and dust, which can result from lead-based automotive fuel and from lead-related industrial emissions, appear to be the most important routes of lead exposure of those evaluated in this study. Elevated lead levels found in paint samples from Volgograd may indicate old undercoats of lead-based paint that could represent a regionally rather than nationally important source of exposure.     

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

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.     

A study of pediatric blood lead levels in a lead mining area in South Africa

This study aimed to determine the blood lead distributions among young children in the lead mining town of Aggeneys in South Africa's Northern Cape Province, and in the comparison community of Pella, about 40 Km away. A further objective of the study was to explore factors associated with elevated blood lead levels. Children aged between 6 and 10 years (average age, 8 years) were studied, 86 from Aggeneys and 68 from Pella. The results showed that blood lead levels among the children of Aggeneys averaged around 16 microg/dL, while in Pella the mean blood lead level equaled 13 microg/dL. Overall, children with raised blood lead levels performed less well at school relative to other children. Within Aggeneys, fathers of "high" lead children tended to shower at work rather than at home, which may have been insufficient to prevent lead from being transported into the home. In conclusion, more stringent environmental control measures are needed, as well as stricter personal hygiene measures, to prevent childhood lead exposure in the mining community.     

Blood lead levels--United States, 1999-2002

Adverse health effects caused by lead exposure include intellectual and behavioral deficits in children and hypertension and kidney disease in adults. Exposure to lead is an important public health problem, particularly for young children. Eliminating blood lead levels (BLLs) >/=10 microg/dL in children is one of the national health objectives for 2010 (objective no. 8-11). Findings of National Health and Nutrition Examination Surveys (NHANES) from the period 1976-1980 to 1991-1994 reveal a steep decline (from 77.8% to 4.4%) in the percentage of children aged 1-5 years with BLLs >/=10 microg/dL. However, BLLs remain higher for certain populations, especially children in minority populations, children from low-income families, and children who live in older homes. This report updates estimates of BLLs in the U.S. population with the latest NHANES data, collected during 1999-2002. The findings indicated that BLLs continued to decrease in all age groups and racial/ethnic populations. During 1999-2002, the overall prevalence of elevated BLLs for the U.S. population aged >/=1 year was 0.7%. BLLs in non-Hispanic black children remained higher than in non-Hispanic white or Mexican-American children, although the proportion of BLLs >/=10 microg/dL in this population decreased (72%) since 1991-1994. Approximately 310,000 children aged 1-5 years remained at risk for exposure to harmful lead levels. Public health agencies should continue efforts to eliminate or control sources of lead, screen persons at highest risk for exposure, and provide timely medical and environmental interventions for those identified with elevated BLLs.     

Prevalence of elevated blood lead levels and evaluation of a lead-risk-screening questionnaire in rural Minnesota

The objectives of the study reported here were to determine the prevalence of elevated blood lead levels in rural Minnesota and to evaluate a lead-risk-screening questionnaire. Blood lead tests and lead risk questionnaires were obtained for a sample of 1,090 children younger than 48 months of age (72 percent of the eligible population) from three rural counties of west-central Minnesota between September 1, 2001, and August 31, 2002. It was found that overall, 2.4 percent of children in the study had blood lead levels of > or = 10 microg/dL (0.48 micromol/L) (results for capillary and venous tests combined), 0.9 percent had venous blood lead levels of > or = 10 microg/dL, and 0.5 percent of study participants had blood lead levels of > or = 20 microg/dL (0.96 micromol/L). Three risk factor questions, when taken together, predicted 90 percent of blood lead levels of > or = 10 microg/dL and all blood lead levels of > or = 20 microg/dL. The study estimated the prevalence of lead poisoning using a sample of the entire population rather than a clinic-based convenience sample. The authors conclude that targeted screening is an effective way to identify lead-poisoned children in rural areas of Minnesota.     

Relationship of blood and bone lead to menopause and bone mineral density among middle-age women in Mexico City

To describe the relationship of blood lead levels to menopause and bone lead levels, we conducted a cross-sectional study on 232 pre- or perimenopausal (PreM) and postmenopausal (PosM) women who participated in an osteoporosis-screening program in Mexico City during the first quarter of 1995. Information regarding reproductive characteristics and known risk factors for blood lead was obtained using a standard questionnaire by direct interview. The mean age of the population was 54.7 years (SD = 9.8), with a mean blood lead level of 9.2 microg/dL (SD = 4.7/dL) and a range from 2.1 to 32.1 microg/dL. After adjusting for age and bone lead levels, the mean blood lead level was 1.98 microg/dL higher in PosM women than in PreM women (p = 0.024). The increase in mean blood lead levels peaked during the second year of amenorrhea with a level (10.35 microg/dL) that was 3.51 microg/dL higher than that of PreM women. Other important predictors of blood lead levels were use of lead-glazed ceramics, schooling, trabecular bone lead, body mass index, time of living in Mexico City, and use of hormone replacement therapy. Bone density was not associated with blood lead levels. These results support the hypothesis that release of bone lead stores increases during menopause and constitutes an internal source of exposure possibly associated with health effects in women in menopause transition.     

Blood lead concentrations < 10 microg/dL and child intelligence at 6 years of age

BACKGROUND: Few studies provide data directly relevant to the question of whether blood lead concentrations < 10 microg/dL adversely affect children's cognitive function. OBJECTIVE: We examined the association between blood lead concentrations assessed throughout early childhood and children's IQ at 6 years of age. METHODS: Children were followed from 6 months to 6 years of age, with determination of blood lead concentrations at 6, 12, 18, and 24 months, and 3, 4, 5, and 6 years of age. At 6 years of age, intelligence was assessed in 194 children using the Wechsler Preschool and Primary Scale of Intelligence-Revised. We used general linear and semiparametic models to estimate and test the association between blood lead concentration and IQ. RESULTS: After adjustment for maternal IQ, HOME scale scores, and other potential confounding factors, lifetime average blood lead concentration (mean = 7.2 microg/dL; median = 6.2 microg/dL) was inversely associated with Full-Scale IQ (p = 0.006) and Performance IQ scores (p = 0.002). Compared with children who had lifetime average blood lead concentrations < 5 microg/dL, children with lifetime average concentrations between 5 and 9.9 microg/dL scored 4.9 points lower on Full-Scale IQ (91.3 vs. 86.4, p = 0.03). Nonlinear modeling of the peak blood lead concentration revealed an inverse association (p = 0.003) between peak blood lead levels and Full-Scale IQ down to 2.1 microg/dL, the lowest observed peak blood lead concentration in our study. CONCLUSIONS: Evidence from this cohort indicates that children's intellectual functioning at 6 years of age is impaired by blood lead concentrations well below 10 microg/dL, the Centers for Disease Control and Prevention definition of an elevated blood lead level.     

Lead and cadmium exposure in children living around a coal-mining area in Yatağan, Turkey

The study was designed to determine asymptomatic lead poisoning prevalence and cadmium exposure of preschool children living in a coal-mining area in Yata?an, Mugla, Turkey. The research was conducted between May and June 2002. The study included 236 children (53.4% female and 46.6% male) who were identified among the healthy children between the ages of 6 months and 6 years, using a systematic sampling method, from the records of the local medical centre of Yata?an. Assessments of the levels of blood lead and cadmium were performed by an atomic absorption spectrophotometer, in the Department of Biophysics, Cerrahpa?a Medical Faculty. The mean age of females and males were 49+/-18 and 43+/-19 months, respectively. The mean blood lead level was 33.8+/-15.6 microg/dL in females and 38.8+/-16.0 microg/dL in males. The mean blood lead level of the males was significantly higher than the females (P<0.05). Correlation analysis showed a statistically significant negative correlation between blood lead level and age in both sex groups (r= -0.367, P<0.001). The blood lead level was found to be > 10 microg/dL in 95.7% and >20 microg/dL in 87.6% of all children. The mean blood cadmium level of all children was 1.31+/-0.72 microg/dL. The blood cadmium level was found to be >0.5 microg/dL, which is considered to be toxic, in 85% of all children. The difference in blood cadmium levels between sexes was not significant. A statistically significant negative correlation was found between blood cadmium level and age of all children (r= -0.382, P<0.001). Although it is not possible to understand from this study what proportion of the biological lead and cadmium burden results from mining waste and what proportion comes from other sources, such as paint and gasoline residue deposited in soil and air, these results do indicate that asymptomatic lead poisoning and cadmium exposure are significant problems in children living in the Yata?an area. In conclusion, environmental lead measurements (house dust, soil, drinking water and air) must be performed, the results must be compared with the normal limits, and precautions must be taken if necessary in the Yata?an area. Future public health research efforts should focus on reducing the excessive levels of lead and cadmium in the environment.     

Cognitive deficits associated with blood lead concentrations <10 microg/dL in US children and adolescents

OBJECTIVE: Lead is a confirmed neurotoxicant, but the lowest blood lead concentration associated with deficits in cognitive functioning and academic achievement is poorly defined. The purpose of the present study was to examine the relationship of relatively low blood lead concentrations-especially concentrations <10 micrograms per deciliter (microg/dL)--with performance on tests of cognitive functioning in a representative sample of US children and adolescents. METHODS: The authors used data from the Third National Health and Nutrition Examination Survey (NHANES III), conducted from 1988 to 1994, to assess the relationship between blood lead concentration and performance on tests of arithmetic skills, reading skills, nonverbal reasoning, and short-term memory among 4,853 children ages 6-16 years. RESULTS: The geometric mean blood lead concentration for children n the study sample was 1.9 microg/dL; 172 (2.1%) had blood lead concentrations > or =10 microg/dL. After adjustment for gender, race/ethnicity, poverty, region of the country, parent or caregiver's educational level, parent or caregiver's marital status parent, serum ferritin level, and serum cotinine level, the data showed an inverse relationship between blood lead concentration and scores on four measures of cognitive functioning. For every 1 microg/dL increase in blood lead concentration, there was a 0.7-point decrement in mean arithmetic scores, an approximately 1-point decrement in mean reading scores, a 0.1-point decrement in mean scores on a measure of nonverbal reasoning, and a 0.5-point decrement in mean scores on a measure of short-term memory. An inverse relationship between blood lead concentration and arithmetic and reading scores was observed for children with blood lead concentrations lower than 5.0 microg/dL. CONCLUSION: Deficits in cognitive and academic skills associated with lead exposure occur at blood lead concentrations lower than 5 microg/dL.     

Inadequate prenatal care and elevated blood lead levels among children born in Providence, Rhode Island: a population-based study

OBJECTIVE: This study was conducted to determine whether children born to mothers receiving inadequate prenatal care are at an increased risk for having an elevated blood lead level during early childhood. METHODS: The authors conducted a population-based study of children born in Providence, Rhode Island, from 1997 to 2001 whose mothers had received adequate, intermediate, or inadequate prenatal care. The children's blood lead levels were compared between groups using bivariate and logistic regression. To understand the regulatory implications and public health impact of changing the definition of an elevated blood lead level, "elevated" was defined as 5 microg/dL, 10 microg/dL, and 15 microg/dL. RESULTS: Children born to mothers who received inadequate prenatal care were at an elevated risk for having an elevated blood lead level later in life. This relationship remained statistically significant for each definition of elevated blood lead level and after controlling for other socio-economic status measures and birthweight (at 5 microg/dL, odds ratio [OR] = 1.36, 95% confidence interval [CI] 1.09, 1.68, p = 0.006; at 10 microg/dL, OR = 1.68, 95% CI 1.26, 2.24, p < 0.0004; at 15 microg/dL, OR = 1.83, 95% CI 1.10, 3.04, p = 0.019) represent an opportune moment to identify expectant mothers living in lead-contaminated environments. CONCLUSIONS: Results suggest that conducting lead screening as a regular part of prenatal care provision could help identify women possibly experiencing ongoing lead exposure and help reduce or prevent exposures to their offspring.     

Brief Report Evaluation of a Childhood Lead Questionnaire in Predicting Elevated Blood Lead Levels in a Rural Community

The accuracy of a lead screening questionnaire in predicting elevated blood lead levels was examined in a pediatric practice in a rural part of New York state. A retrospective chart review was used to collect data on children ages 9 to 24 months who presented for well-child visits. Children with both questionnaire and lead level results available in the chart were included in the study (n = 171). The mean blood lead level among all children was 1.6 microg/dl (median = 2.0 microg/dl, range 0 to 24 microg/dl). Four children (2.3%) had elevated lead levels (greater than 10 microg/dl), with levels for two of these children being greater than 20 microg/dl. Although our lead screening questionnaire was expanded from the standard 1991 CDC questionnaire by the inclusion of six additional items, it was not especially useful in predicting elevated blood lead levels above 10 microg/dl. However, the questionnaire exhibited some utility in predicting marked elevations in blood lead levels (over 20 microg/dl). Although results in other geographic areas might differ, the lead questionnaire may have value by enhancing parents' awareness of potential lead hazards in their children's environment and may prove to be more useful in areas of high risk to lead exposure.     

Children in Illinois with elevated blood lead levels, 1993-1998, and lead-related pediatric hospital admissions in Illinois, 1993-1997

OBJECTIVE: This study uses screening and hospitalization data to describe the prevalence of childhood lead poisoning in Chicago and the rest of the state of Illinois. METHODS: The authors used aggregate data published by the Illinois Department of Public Health on blood lead testing of children ages 0-6 years and data on lead-related hospital admissions of children ages 0-6 years, drawn from an administrative dataset compiled as part of a state initiative. RESULTS: No clear time trends in the percentage of children with elevated blood lead levels (defined as >15 micrograms per deciliter [microg/dL] or >45 microg/dL) were evident in either Chicago or the rest of Illinois. The proportions of children with elevated blood lead levels in Chicago and in the rest of Illinois did not decline at the dramatic rate seen in the US as a whole during the 1990s. Over a five-year period, in-hospital charges of $7.7 million were generated for the care of lead-poisoned children ages 6-16 in Chicago alone. CONCLUSION: Surveillance data, analyzed at the appropriate geographic level, can be used to focus resources on high-risk areas and to evaluate prevention efforts.     

Lead exposure among small-scale battery recyclers, automobile radiator mechanics, and their children in Manila, the Philippines

Blood lead (PbB) and hemoglobin levels (Hb) were determined in 40 battery repair/recycling shop workers, 16 radiator repair shop workers, and 20 children living in the immediate vicinity of these shops. Unexposed residents with similar socioeconomic status were also investigated. Mean PbB level was significantly higher for battery workers (54.23 microg/dL) when compared to radiator workers (20.04 microg/dL) and unexposed adults (12.56 microg/dL) (P<0.001). Among battery workers, 94% had PbB levels above the WHO permissible exposure limit of 40 microg/dL for males and 30 microg/dL for females. There was no demarcation between workplace and living quarters; therefore, workers' families were similarly exposed to hazards. Children living in the immediate vicinity of battery shops also had significantly higher mean PbB levels (49.88 microg/dL) compared to radiator shop children (11.84 microg/dL) and unexposed children (9.92 microg/dL). For workers with PbB > 40 microg/dL, 90% were anemic (Hb < 13 g/dL for males and <11.5 g/dL for females). Linear regression showed a correlation (r=-0.214; P=0.03) between Hb level and log(10)PbB. There was no significant relationship between anemia and blood lead in children (r=-0.146). We conclude that radiator repair activities appeared to increase the body burden of lead, although not up to a level significantly different from unexposed counterparts. Battery recycling/repair activities, however, significantly increased blood lead levels in workers and their children.