Trends in blood lead levels among children--Boston, Massachusetts, 1994-1999

Data from the National Health and Nutrition Examination Survey and national childhood blood lead surveillance data from 19 states indicated that average blood lead levels (BLLs) in young children decreased during the late 1990s (1-3). The proportion of children tested who had BLLs >10 microg/dL declined from 10.5% in 1996 to 7.6% in 1998, although the proportion was higher in certain counties (3). To determine whether a similar decline had occurred in Boston, Massachusetts, where a high proportion of children are tested each year, and whether any changes were similar in high- and low-risk neighborhoods, CDC, in collaboration with the Boston Childhood Lead Poisoning Prevention Program (BCLPPP) performed an analysis of BLLs among children aged 6-72 months in Boston during 1994-1999. The results indicate that BLLs in Boston declined during this period, but because of the geographic variation in lead exposure, continued surveillance will be necessary to eliminate childhood lead poisonings.     

Lowering time trend of blood lead levels in Belgium since 1978

Since 1978, the biological screening of the Belgian population was regularly monitored by measuring blood lead levels. Over 11 years, 6070 samples were analyzed in urban, rural, and industrial areas. The median values of blood lead concentration dropped from 170 to 78 micrograms/liter of blood, i.e., a lowering of about 55%. The trend persists when taking into account some individual characteristics which influence blood lead levels such as gender, age, tobacco, and areas. These influences and the possible environmental causes of the observed trend are discussed.     

Decreasing blood lead in Swedish children, 1978-1988

The geometric mean of the blood lead concentrations in 1,781 samples obtained from children during 1978 to 1988 was 46.9 micrograms/l (0.23 mumol/l) (range: 14-250 micrograms/l [0.07-1.2 mumol/l]). There was a significant (p less than .001) decrease in blood lead concentrations of 7%/y in rural and urban areas. In 134 children who were sampled twice, the decrease over 2-y periods was 14%. The striking decrease in blood lead levels is most likely the result of a reduction of lead additives in motor fuel during this period.     

Evolution of blood lead levels in urban French population (1979-1995)

BACKGROUND: The aim of the Council Directive of 29 March 1977 of the European Union was to measure non-occupational lead exposure levels in the general adult populations of European countries through biological monitoring. In France, such measurements were carried out during 1979 and 1982 in eight metropolitan areas (having more than 500 000 inhabitants), a period during which the lead content of petrol was decreased. The aim of this study conduct in 1995 was to evaluate the exposure trend to lead. METHODS: In 1995 this measurement was repeated, only in the three largest urban areas (Paris, Marseilles and Lyons). The same sampling method used in the first two campaigns was retained to ensure that the results of 1995 could be compared with those from 1979 and 1982. RESULTS: In these three metropolitan areas, the average blood lead levels decreased by the order of 60 microg/l between the beginning of the 1980's and 1995. This represents a fall of more than 50%. CONCLUSIONS: Certainly car pollution is not the only vector of dissemination of lead in the centre of urban zones, but it is there that the most sustained efforts at eradication have been made. The improvement we have observed is probably due to the policy of eliminating lead from petrol. In conclusion, the blood lead levels in French urban populations seem to have greatly decreased from those of the early 1980s.     

Trends in occupational lead exposure since the 1978 OSHA lead standard

BACKGROUND: The purpose of the study was to evaluate trends in occupational lead exposures throughout U.S. industry after the establishment of the general industry lead standard in 1978 and the construction industry standard in 1993. METHODS: Lead exposure measurements collected by the Occupational Safety and Health Administration (OSHA) under their compliance and consultation programs were analyzed. Time trends in the distributions of exposure levels were evaluated graphically. Trends in the proportion of exposures above the OSHA permissible exposure limit (PEL) were analyzed using logistic regression models. RESULTS: The distribution of lead exposure levels declined over the study time period for general industry, but not for construction. The median exposure levels for general industry facilities decreased five- to tenfold. Logistic regression models reveal statistically significant declines in the odds of a lead exposure exceeding the PEL. CONCLUSIONS: This study provides evidence for relatively large decreases in lead exposure levels in general industry facilities over time. The study does not provide similar evidence for the construction industry. Given the limited number of years of data available since the implementation of the revised construction standard for lead, re-analysis of lead exposure levels within this industry would be worthwhile when more data become available.     

Substantial decrease of blood lead in Swedish children, 1978-94, associated with petrol lead.

OBJECTIVES--To study the potential impact of environmental exposure to petrol lead, residential area, age, sex, and lead exposing hobby, on blood lead concentrations (BPb) in children. METHODS--In the south of Sweden, yearly from 1978-94, BPb was measured in 1230 boys and 1211 girls, aged between 3 and 19 (median 10; quartiles 9 and 12) years. RESULTS--For the samples of 1978, the geometric mean (GM) was 67 (range 30-250) micrograms/l in boys and 53 (18-161) micrograms/l in girls, whereas the corresponding GMs for 1994 were 27 (12-122) and 23 (12-97) micrograms/l. The sex difference was present only in children over eight. Moreover, residential area affected BPb; in particular, children living near a smelter area had raised BPbs. There was a clear ecological relation between BPb (adjusted GM) and annual lead quantity in petrol sold in Sweden, which was estimated to be 1637 tonnes in 1976 and 133 tonnes in 1993 (P < 0.001, ecological linear regression analysis, where a two year lag of petrol lead was applied). In the 171 boys and 165 girls who were sampled twice with an interval of one to four years, the decreases in BPb were estimated to be 6% (95% confidence interval 4%-8%) and 10% (8%-13%)/year, respectively. CONCLUSIONS--The present report points out the considerable beneficial effect of the gradual banning of petrol lead on the lead exposure affecting the population and differential sex specific BPb patterns due to a pronounced age effect in girls, which may be caused by older girls' lower food intake per kg of body weight, lower lung ventilation, cleaner life style, and loss of blood lead through menstrual bleedings.     

Morbidity and mortality of radical cystectomy (1971-78 and 1978-85).

The mortality after radical cystectomy with urinary diversion has been reduced from 11% in 53 patients operated on during 1971-78, to 2.5% in a similar group of 120 patients operated on during 1978-85. Amongst the latter, mortality varied from 0 amongst 32 non-irradiated patients, to 1 (3%) of 33 after planned preoperative radiotherapy and 2 (3.6%) of 55 after previous radical radiotherapy. The improvement in results appears to be due to a number of factors including routine intensive care in the early postoperative phase, with epidural analgesia, and meticulous attention to haemostasis and the technical details of construction of the ileal conduit.     

Trends in the incidence of major salivary gland cancer in Spain (1978-2002)

Objective

To analyze the trend in the incidence rates of major salivary gland cancer in population-based cancer registries in Spain.

Methods

The following Spanish cancer registries with a minimum follow-up period of 10 years were selected: Albacete, Asturias, Granada, Murcia, Navarre, Tarragona and Zaragoza. Adjusted incidence rates were calculated. Joinpoint software was utilized to calculate change estimations in incidence rates for the period 1991-2001.

Results

Joinpoint analysis revealed a statistically significant decreasing trend with an annual percent change of –5.3% (95% CI: -8.7 to –1.8).

Conclusion

The incidence of major salivary gland cancers in Spain was low and a decreasing trend was identified between 1991 and 2001.     

Soil lead abatement and children's blood lead levels in an urban setting.

OBJECTIVES: The effect of abating soil lead was assessed among Baltimore children. The hypothesis was that a reduction of 1000 parts per million would reduce children's blood lead levels by 0.14 to 0.29 mumol/L (3-6 micrograms/dL). METHODS: In 2 neighborhoods (study and control), 187 children completed the protocol. In the study area, contaminated soil was replaced with clean soil. RESULTS: Soil lead abatement in this study did not lower children's blood lead. CONCLUSIONS: Although it did not show an effect in this study, soil lead abatement may be useful in certain areas.     

Home refinishing, lead paint, and infant blood lead levels.

We measured the blood lead levels of 249 infants semi-annually from birth to two years of age; we sampled the home paint and recorded any recent home refinishing activity. Mean blood lead from birth to age 2 years did not vary systematically with age but did correlate significantly with the amount of lead in the indoor paint (p less than .01). Refinishing activity in homes with high lead paint was associated with elevations of blood lead averaging 69 per cent.     

Air and blood lead levels in a battery factory.

Blood lead (Pb B) and air lead (Pb A) exposure levels were studied in workers (62) in a battery plant. Thirty-five battery workers had Pb B higher than 60 μg/100ml (OSHA Proposed Biologic Limit Value, (BLV), 1975). Fifty-eight workers had Pb Bs exceeding 40 μg/100 ml (OSHA Proposed BLV, 1978). Average Pb A for 33 battery workers was greater than 100 μg/m³, the newly recommended TWA. Average Pb A of approximately 50 μg/m³, (6 workers), 85 μg/m³ (17 workers), and 190 μg/m³ (10 workers) were associated with virtually identical mean Pb B (55.0, 59.5, and 58.4 μg/100ml). For 10 of 29 battery workers, Pb A less than 100 μg/m³ was associated with Individual Pb B greater than 60 μg/100 ml. At exposure levels of 329 μg/m³ (15 workers), 885 μg/m³ (3 workers), and 1187 μg/m³ (4 workers), associated mean Pb B was 75.2, 76.3, and 90.7 μg/100 ml, respectively. Complaints of fatigue, headache, abdominal pain, and loss of appetite were more frequent among 35 workers with Pb B > 60 μg/100 ml compared to 26 workers with Pb B < 60 μg/100 ml (relative risks 1.5, 1.4, 1.9, and 1.9, respectively). The relationship between group Pb A and individual Pb B was expressed by the equation: log Pb B (μg/100 cc) = 1.430 + 0.165 × log Pb A (μg/m³), r = 0.69. Battery factory data do not support the assumption that if Pb A were kept at or below 100 μg/m³, the blood lead levels would be less than 60 μg/100 ml.     

Environmental urban lead exposure and blood lead levels in children of Mexico City.

Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil, water, and glazed ceramics were obtained from the participants' households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 micrograms/dl with a mean of 9.9 micrograms/dl (SD 5.8 micrograms/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 micrograms/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used to prepare children's food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children's hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics.     

Moderate lead poisoning: trends in blood lead levels in unchelated children.

The appropriate clinical management of children who are moderately poisoned with lead (Pb) is under active investigation. To determine the pattern of change in blood Pb (BPb) levels in the absence of chelation therapy, we followed moderately Pb-poisoned children (initial blood Pb levels 1.21-2.66 mumol/l or 25-55 micrograms/dl) for 6 months with repeated BPb level measurements. Chelation therapy was not administered because all the children had negative lead mobilization tests indicating limited response to the chelating agent, calcium disodium edetate (CaNa2EDTA). Eligible children received the following interventions: notification of the health department to remediate lead hazards; reinforced educational efforts about the toxicity sources and treatment of Pb during 10 clinic and 3 home visits; and iron therapy for children with ferritin levels less than 16 micrograms/l. To quantify the lead paint hazards in the home, we combined a visual rating of the surfaces (intact to peeling) with an X-ray fluorescence (XRF) measurement of the lead content of the painted surface. The sum of these assessments is termed the home environmental score (HES). Data were analyzed from 79 children. BPb levels declined by 27%, on average, over 6 months. HES was correlated with BPb at enrollment, but neither the initial nor later HES measurements predicted BPb at other time points. The HES was highest at enrollment and declined by 50% and 75% at the second and third home visits, respectively. However, only a minority of the children (20%) achieved an HES of 0, indicating no lead paint hazards at home. Despite some ongoing Pb exposure, a parallel fall in BPb levels was observed in subgroups of children with either initially low or high HES (above or below the median HES of 37). Iron status did not account for the change in BPb levels. These data provide evidence that our measure, the HES, is quantifiably related to BPb levels in children, that this correlation is significant only prior to intervention; and that BPb levels decline in children who are moderately poisoned with Pb after they are enrolled in a comprehensive intervention program, even in the absence of chelation therapy and in the presence of ongoing lead paint exposure and Fe deficiency.     

Elevated blood lead levels among adults in Massachusetts, 1991-1995

OBJECTIVE: Lead poisoning, the oldest recognized occupational disease, remains a danger for children and adults. Data collected for 664 cases reported to the Massachusetts Occupational Lead Registry in 1991-1995 were summarized in a 1998 state report. Here, the authors present some of the key findings from that report for a wider audience. METHODS: The authors summarize key findings of the 1998 state report. FINDINGS: Construction workers, in particular licensed deleaders and house painters, accounted for almost 70% of occupational cases involving blood lead levels > or = 40 micrograms of lead per deciliter (mcg/dl) of blood. Among 100 workers with the highest blood lead levels (> or = 60 mcg/dl), 29% were house painters. Hispanic workers were over-represented in the Registry. A small proportion of cases were non-occupational, typically associated with recreational use of firing ranges or do-it-yourself home renovations. CONCLUSION: Lead poisoning is a preventable disease, yet these data indicate that additional prevention efforts are warranted.     

Tofu consumption and blood lead levels in young Chinese adults.

Tofu is a commonly consumed food in China. Tofu may interfere with lead absorption and retention because of its high calcium content. In this observational study, the authors examined whether dietary tofu intake was associated with blood lead levels among young adults in Shenyang, China. The analyses included 605 men and 550 women who completed baseline questionnaires and had blood lead measurements taken in 1996-1998 as part of a prospective cohort study on reproductive health. Mean blood lead levels were 13.2 microg/dl in men and 10.1 microg/dl in women. Blood lead levels were negatively associated with tofu intake in both genders. A linear trend test showed a 3.7% (0.5-microg/dl) decrease in blood lead level with each higher category of tofu intake (p = 0.003). The highest tofu intake group (> or =750 g/week) had blood lead levels 11.3% lower (95% confidence interval: 4.1, 18.0) than those of the lowest tofu intake group (<250 g/week). In all regression models, data were adjusted for gender, age, height, body mass index, district, cigarette smoking, alcohol drinking, education, occupation, use of vitamin supplements, season, and dietary intake of meat, fish, vegetables, eggs, and milk. In conclusion, the authors found a significant inverse dose-response relation between tofu consumption and blood lead levels in this Chinese population.     

Elevated blood lead levels in refugee children--New Hampshire, 2003-2004

As a result of reductions in lead hazards and improved screening practices, blood lead levels (BLLs) in children aged 1-5 years are decreasing in the United States. However, the risk for elevated BLLs (> or =10 microg/dL) remains high for certain populations, including refugees. After the death of a Sudanese refugee child from lead poisoning in New Hampshire in 2000, the New Hampshire Department of Health and Human Services (NHDHHS) developed lead testing guidelines to screen and monitor refugee children. These guidelines recommend 1) capillary blood lead testing for refugee children aged 6 months-15 years within 3 months after arrival in New Hampshire, 2) follow-up venous testing of children aged <6 years within 3-6 months after initial screening, and 3) notation of refugee status on laboratory slips for first tests. In 2004, routine laboratory telephone reports of elevated BLLs to the New Hampshire Childhood Lead Poisoning Prevention Program (NHCLPPP) called attention to a pattern of elevated BLLs among refugee children. To develop prevention strategies, NHDHHS analyzed NHCLPPP and Manchester Health Department (MHD) data, focusing on the 37 African refugee children with elevated BLLs on follow-up for whom complete data were available. This report describes the results of that analysis, which indicated that 1) follow-up blood lead testing is useful to identify lead exposure that occurs after resettlement and 2) refugee children in New Hampshire older than those routinely tested might have elevated BLLs. Refugee children in all states should be tested for lead poisoning on arrival and several months after initial screening to assess exposure after resettlement.     

Elevated blood lead levels in children of construction workers.

OBJECTIVES: This study examined whether children of lead-exposed construction workers had higher blood lead levels than neighborhood control children. METHODS: Twenty-nine construction workers were identified from the New Jersey Adult Blood Lead Epidemiology and Surveillance (ABLES) registry. Eighteen control families were referred by workers. Venous blood samples were collected from 50 children (31 exposed, 19 control subjects) under age 6. RESULTS: Twenty-six percent of workers children had blood lead levels at or over the Centers for Disease Control and Prevention action level of 0.48 mumol/L (10 micrograms/dL), compared with 5% of control children (unadjusted odds ratio = 6.1; 95% confidence interval = 0.9, 147.2). CONCLUSIONS: Children of construction workers may be at risk for excessive lead exposure. Health care providers should assess parental occupation as a possible pathway for lead exposure of young children.