Lead levels in blood bank blood

Although blood bank blood is usually screened for dangerous pathogens, the presence of toxic metals in blood has received little attention. Population blood lead levels have been declining in the United States, but occasional high outliers in blood lead concentration can be found--even when mean levels of blood lead are low. We sampled 999 consecutive blood bank bags from the King/Drew Medical Center, used between December 1999 and February 2000. The geometric mean blood lead level was 1.0 microg/dl (0.048 micromol/l), but 0.5% of the samples had lead levels that exceeded 10 microg/dl, and 2 samples had lead levels that exceeded 30 microg/dl. The 2 samples with the highest lead levels could have presented an additional risk to infants if they were used for blood replacement. Therefore, even in countries with generally low population blood lead levels, blood bank blood should be screened for lead concentration prior to use with infants.     

Low-Level Lead Exposure and Blood Lead Levels in Children: A Cross-Sectional Survey

The authors studied 53 girls (44.5%) and 66 (55.5%) boys in Karachi, Pakistan, to determine their blood lead levels. The association between blood lead levels/water lead levels and the possible risk factors and symptoms associated with lead toxicity was explored. The mean lead level for the entire group was 7.9 μg/dl (standard deviation = 4.5 μg/dl). Thirty (25.2%) of the children had lead levels that exceeded 10 μg/dl; 12 (10.0%) of these had lead levels that exceeded 15 μg/dl. Thirteen (20.9%) of the children under the age of 6 yr (n = 62) had lead levels greater than 10 μg/dl, and 6 (9.6%) had levels in excess of 15 μg/dl. The authors found no association (p > .05) between high lead levels in water and blood lead levels in children. Mean blood lead levels were highest in the group of children exposed to various risk factors for lead absorption (e.g., exposure to paint, remodeling, and renovation; use of lead utensils; pica). There was a significant association between a history of exposure to paint/renovation activities and a history of pica. High blood lead levels in the children in Karachi stress the urgency for actions that control lead pollution. Screening programs should be instituted by the state. Individuals must become aware of lead's toxicity, and they must avoid substances that contain lead.     

Early Pregnancy Blood Lead and Spontaneous Abortion

Although evidence tends to suggest that high levels of lead exposure increase the risk of spontaneous abortion, we do not yet know whether moderate- to low-level exposure elevates risk. Among 351 women (aged 16 to 35 years, with single pregnancies) who were registered for a longitudinal study, 15 (4.3%) women experienced spontaneous abortion after the 12th week of gestation and before the 20th week. We collected participants' blood samples during the first trimester of pregnancy (8–12 weeks) for lead measurement by inductively coupled plasma-mass spectrometry. Mean ± standard deviation of blood lead was 3.8 ± 2.0 μg/dl (range 1.0–20.5 μg/dl) with a geometric mean of 3.5 μg/dl. Mean blood lead concentrations did not differ significantly between spontaneous abortion cases and ongoing pregnancies (3.51 ± 1.42 and 3.83 ± 1.99 μg/dl, respectively). The findings suggest that in apparently healthy women, low blood lead levels (mean <5 μg/dl) measured in early pregnancy may not be a risk factor for spontaneous abortion.     

Blood Lead Levels in 2- to 3-Year-Old Children in the Greater Bilbao Area (Basque Country,Spain): Relation to Dust and Water Lead Levels

The objectives of this study were to determine blood lead levels in 2-y-old children in the Greater Bilbao Area (Basque Country, Spain) and to compare those levels with the lead content of different media (i.e., house dust, park dust and soil, and water) in the child's environment. Between May and September of 1992, 138 children, aged 2 to 3 y, were studied. All children were attended by pediatricians within the public health-care network, and their parents volunteered for the study. A venous blood sample was drawn from each child and was analyzed for lead level, and the parents answered a questionnaire that addressed the socioeconomic background and habits of the children. The environment was investigated in 42 cases. Blood lead levels exceeded 15 μg/dl in 2% of the children, and 14% of the children had levels that exceeded 10 μg/dl (geometric mean = 5.7 μg/dl [4.7–6.7 μg/dl]). Blood lead levels were higher among (a) children whose mothers worked outside the home, (b) children whose fathers had only a primary-level education, and (c) children who lived in houses constructed prior to 1950. The geometrical averages of lead in house dust, park soil, and park dust were 595, 299, and 136 μg/g, respectively. Statistically significant linear correlation was found between blood lead level and lead content in park dust, a finding that explained a 9% variation in blood lead level; a subgroup of these children was also found to have a strong linear association between blood lead and lead content in house dust.     

Lead levels in Maryland construction workers

A cross-sectional study of unionized construction workers not currently known to be performing lead work was conducted. Participants completed an interviewer-administered questionnaire obtaining information about demographics, work history, other possible sources of lead exposure and health status (including hypertension, noise-induced hearing loss and renal disease). Blood was then obtained via venipuncture for whole blood lead level, hematocrit and free erythrocyte protoporphyrin determination. Two hundred and sixty-four Maryland construction workers had median whole blood lead determinations of 7 μg/dl and mean values of 8.0 μg/dl, with a skewed distribution ranging from 2 to 30 μg/dl. None were currently engaged in known lead work. Blood lead levels were significantly higher for the 124 who had ‘ever’ worked in demolition (8.8 μg/dl vs. 7.2 μg/dl, p = .004), and for the 79 who had ever burned paint and metal and welded on outdoor structures compared to the 48 who had done none of these activities (8.6 μg/dl vs. 6.8 μg/dl, p = .01). The 58 workers who had ever had workplace lead monitoring performed had higher lead levels (9.7 vs. 7.5 μg/dl, p = .003). Blood lead levels increased with age, and cigarette smoking. African Americans (N = 68) had higher lead levels (9.1 vs. 7.5 μg/dl, p = .01). There were only two women in the study, one with a lead level of 21 μg/dl and one, 7 μg/dl. Blood lead levels did not predict either systolic or diastolic blood pressure in this population. However, there was a significant interaction between race and lead as predictors of blood pressure, with blacks demonstrating a trend-significant correlation, and whites showing a nonsignificant but negative association. Demolition and hotwork on outdoor structures are known to cause acute episodes of lead poisoning. They also appear to cause slight but persistent increases in blood lead levels. Future workplace regulation should recognize and seek to maintain the low baseline now apparent even in urban, East Coast, construction workers. Am. J. Ind. Med. 31:188–194, 1997. © 1997 Wiley-Liss, Inc.     

Lead and Cadmium Exposure from Contaminated Soil among Residents of a Farm Area near an Industrial Site

In this study, the authors determined the degree of lead and cadmium exposure in a population that resided in an area with contaminated soil. The extent of exposure from soil pollution was also assessed. Lead and cadmium concentrations in blood of children and adults who resided in the contaminated area were measured, and cadmium concentration in urine of adults was also determined. An adult control group was recruited from a non-polluted area. The mean blood lead level in adults who resided in the polluted area was 9.8 μg/dl, compared with a mean level of 6.8 μg/dl in controls (p = .004). Urinary cadmium levels were well below the level associated with onset of symptoms, but the differences between levels in residents of the contaminated area (0.54 μg/gm creatinine) and levels in the controls (0.37 μg/gm creatinine) indicated that life-long cadmium exposure had been higher among the residents of the contaminated area (p = .086). The mean blood lead level and mean blood cadmium level in children were 5.2 μg/dl (maximum = 7.90 μg/dl) and 0.10 μg/l, respectively. Lead in soil accounted in large part for the differences in blood lead levels in children; however, blood cadmium levels were not associated with soil cadmium levels, but, rather, with consumption of home-grown vegetables.     

Editorial: The Bhopal Gas Disaster: It's Not Too Late for Sound Epidemiology

In Russia, hair, rather than blood, is usually used as a substrate for screening children for lead poisoning. We attempted to gauge the accuracy of this method by comparing these two methods. The evaluation was done in Saratov, Russia. We collected hair and blood samples from 189 children who attended 11 kindergartens. Their mean blood lead concentration was 9.8 μmlg/dl (range = 3.1–35.7 μmlg/dl), and their mean hair lead concentration was 7.2 μmlg/g (range = 1.0–7.2 μmlg/g [i.e., 1.0 being the lowest detectable limit]). Hair lead concentration as a screening method had 57% sensitivity and resulted in 18% of the children being classified as false-negatives. We conclude, therefore, that measuring hair lead concentration is not an adequate method with which to screen children for lead poisoning.     

Different Associations of Blood Lead,Meso 2,3-Dimercaptosuccinic Acid (DMSA)-Chelatable Lead,and Tibial Lead Levels with Blood Pressure in 543 Former Organolead Manufacturing Workers

In this study, the authors' objective was to determine the influence of blood lead, meso 2,3-dimercaptosuccinic acid (DMSA)-chelatable lead, and tibial lead on systolic and diastolic blood pressures and on hypertension in 543 former organolead manufacturing workers. All workers had past exposure to inorganic and organic lead. The authors used linear regression to model systolic and diastolic blood pressure separately, and logistic regression was used for the modeling of hypertension status (i.e., systolic blood pressure > 160 mm Hg, diastolic blood pressure ≥ 96 mm Hg, or current use of antihypertensive medications). Blood lead, DMSA-chelatable lead, and tibial lead levels had means (standard deviations appear within parentheses) of 4.6 μmlg/dl (2.6 μmlg/dl), 19.3 μmlg (17.2 μmlg), and 14.4 μmlg/g (9.3 μmlg/g) respectively. The authors adjusted for covariates, and they found that blood lead was a predictor of (1) both systolic and diastolic blood pressures and (2) hypertension status in men ≤ 58 y of age. DMSA-chelatable lead and tibial lead were not associated with any of the blood pressure measures. Systolic blood pressure was elevated by blood lead levels as low as 5 μmlg/dl. We speculate that lead may have a transient influence on blood pressure that is related to target dose levels obtained once release of lead from body stores has occurred.     

Blood lead levels in Japanese children: Effects of passive smoking

Blood lead levels (BLLs) of 188 pediatric patients were measured and their parents were queried as to the smoking style in their home. Their mean BLL was 3.16 μg/dl, which was among the lowest levels in the world, and none of them had levels of over 10 μ g/dl. Preschool children ( 1 to 6 years of age) with parents who smoked in the same room had a significantly higher BLL (mean; 4.15 μ g/dl) than those with parents who never smoked (mean; 3.06 μ g/dl) (P<0.01). However, the mean BLL of school children (6 to 15 years of age) with parents who smoked in the same room was not significantly different from that of school children with parents who never smoked. Passive smoking caused an increase of the BLL only in preschool children in Japan. This is probably because preschool infants spend much more time with their parents and have much more contact with passive smoking than school children and, additionally young infants have a limited ability to excrete lead from the body.     

Blood Lead Levels in Children in South Central Los Angeles

We retrospectively reviewed 3 679 pediatric records from King/Drew Medical Center, south central Los Angeles, between 1991 and 1994. Blood lead levels of children were followed to age 18 y. Patients were not referred specifically for lead poisoning. The sample was primarily Latino. Geometric mean blood lead peaked at 6.7 μg/dl (0.32 μmol/l) between 2 and 3 y of age. There was a downward secular trend and a seasonal trend. Males had higher lead levels than females. Children who lived in several zipcode areas, in which the lowest family incomes were reported, had higher lead levels. More Latino children had higher lead levels than African American children. Latino children (i.e., 20.2%) who were 1–5 y of age had blood lead levels that were ≤ 10 μg/dl. Young Latino children in this zone of Los Angeles may be at increased risk for lead exposure.     

Lead exposure in stained glass workers

To evaluate lead exposure in stained glass workers, we measured blood lead levels in 12 professional glass workers, in 5 hobbyists, and in 4 workers' family members. Professional workers lead levels (mean 20.7 μg/dl) were higher than hobbyists' (11.6 μg/dl) (P = 0.02) or family members' (11.3 μg/dl). Levels increased with years worked, hours worked per week, and percentage of work involving lead. The mean lead concentration in settled dust samples from a stained glass workshop was 11,000 parts per million. Stained glass workers are at increased risk of lead exposure.     

Early pregnancy blood lead and spontaneous abortion

Although evidence tends to suggest that high levels of lead exposure increase the risk of spontaneous abortion, we do not yet know whether moderate- to low-level exposure elevates risk. Among 351 women (aged 16 to 35 years, with single pregnancies) who were registered for a longitudinal study, 15 (4.3%) women experienced spontaneous abortion after the 12th week of gestation and before the 20th week. We collected participants' blood samples during the first trimester of pregnancy (8-12 weeks) for lead measurement by inductively coupled plasma-mass spectrometry. Mean ± standard deviation of blood lead was 3.8 ± 2.0 μg/dl (range 1.0-20.5 μg/dl) with a geometric mean of 3.5 μg/dl. Mean blood lead concentrations did not differ significantly between spontaneous abortion cases and ongoing pregnancies (3.51 ± 1.42 and 3.83 ± 1.99 μg/dl, respectively). The findings suggest that in apparently healthy women, low blood lead levels (mean < 5 μg/dl) measured in early pregnancy may not be a risk factor for spontaneous abortion.     

新生儿脐带血铅铜锌水平与血细胞指数及铁代谢指标的关系

目的:了解新生儿脐带血铅、铜、锌水平与血细胞指数及铁代谢指标之间的关系。方法:采用横断面描述性研究方法,分别测定纳入研究的433名新生儿脐带血铅、铜、锌、铁水平,铁蛋白、血红蛋白浓度以及白细胞、红细胞计数,分析其相关性。结果:新生儿脐血铅、铜、锌以及铁浓度分别为4.8(2.9,8.1)μg/dl[中位数(P25,P75)],88.4(34.3,156.8)μg/dl,104.2(49.8,176.2)μg/dl和98.5(32.7,137.1)μg/dl。低血铅组新生儿脐血血锌以及血白细胞计数均显著低于高血铅组新生儿,而血清铁水平则显著高于高血铅组新生儿(P<0.05)。脐血血铅浓度与血铜、血锌浓度及白细胞水平成明显正相关(相关系数r分别为0.12,0.24及0.30,P均<0.05),而与血清铁成明显负相关(r=-0.25,P<0.05)。结论:孕期铅、铜等微量元素与胚胎期造血以及铁代谢密切相关。     

Lead-Glazed Ceramic Ware and Blood Lead Levels of Children in the City of Oaxaca,Mexico

Although Mexico substantially reduced use of leaded gasoline during the 1990s, lead-glazed pottery remains a significant source of population exposure. Most previous studies of lead in nonoccupationally exposed groups in Mexico have been conducted in the Mexico City metropolitan area. Oaxaca, a poor southern state of Mexico, has a centuries-old tradition of use of low temperature lead-glazed ceramic ware manufactured mainly by small family businesses. We measured blood lead levels in 220 8–10-y-old children (i.e., not from pottery-making families) who were students in the innercity of Oaxaca and in the mothers of all children. The geometric mean blood lead level of the children was 10.5 μmlg/dl (+7.0/–4.3 μmlg/dl standard deviation; range = 1.3–35.5 μmlg/dl). The corresponding mean value for the mothers was 13.4 (+9.0/–5.4 μmlg/dl standard deviation; range = 2.8–45.3 μmlg/dl). We used cutoffs that were greater than or equal to 10 μmlg/dl, 20 μmlg/dl, and 30 μmlg/dl, and we determined that 54.9%, 10.3%, and 3.0% of the children were at or above the respective criteria. We accounted for 25.2% of the variance in blood lead levels of the children, using maternal responses to a questionnaire that assessed possible lead sources in a linear multiple-regression model. The most important factors related to lead levels were family use of lead-glazed pottery, use of animal fat in cooking, and family income. The addition of maternal blood lead level to the model increased accounted variance in blood lead to 48.0%. In logistic-regression modeling of children's blood lead levels, we used a cutoff of greater than or equal to 10 μmlg/dl, and we found that use of lead-glazed pottery was the most important of all questionnaire items that were predictive of blood lead levels (odds ratio = 2.98). In Oaxaca, as is the case elsewhere in Mexico, lead-glazed ceramic ware remains a significant risk factor for elevated blood lead levels in children.     

Blood Lead Concentrations and Pregnancy Outcomes

In this study, the authors related blood lead concentrations to Apgar scores, birth weight, gestational age, small-for-gestational age, and hypertension in pregnancy (HIP)/toxemia. Data and blood were collected 4 times during pregnancy from 705 women, aged 12–34 yr. Blood lead concentrations, measured by atomic absorption spectrophotometry, were related to reproductive outcomes, abstracted from medical records. Average blood lead concentrations were 1.2 μg/dl (standard error = ± 0.03). Maternal blood lead concentrations were related significantly to HIP/toxemia—before and after adjusting for age, calcium intake, and race/ethnicity (p < .03). Longitudinal regression analyses revealed that blood lead concentrations in women with HIP/toxemia changed by 0.02 μg/dl for every 0.01 μg/dl change in women without HIP/toxemia. Maternal blood lead concentration and its change were not significantly associated with other reproductive outcomes. Low levels of maternal blood lead concentrations were significantly associated with HIP/toxemia.     

Relationship Between Blood Lead Levels and Hematological Indices in Pregnant Women

Several studies have revealed a negative association between blood lead levels and hematological impairment. In this cross-sectional study, we examined the relationship between blood lead levels and hematological indices in 292 pregnant women from Durango, Mexico. Apparently healthy pregnant women, aged 14–41 years and at 3–41 weeks of gestation, were recruited between June 2007 and May 2008. Blood lead and hematological indices were measured. The mean blood lead was 2.79 ± 2.16 μg/dL, and lead levels ≥5 μg/dL were detected in 25 women (8.6%). Hemoglobin, hematocrit, and red blood cells count were significantly higher in pregnant women with a blood lead concentration of ≥5 μg/dL than the group with lower blood lead levels (p < .05). Mean corpuscular volume and mean corpuscular hemoglobin were not significantly related to lead levels. Hemoglobin and hematocrit showed a non-significant positive correlation with blood lead, but the correlation between red blood cell count and blood lead levels was statistically significant (r = 0.185, p = .002). The findings suggest that a positive association between blood lead and some hematological indices may occur at relatively low blood lead concentration (mean < 5 μg/dL).     

Blood lead levels in children in Perth,Western Australia

Abstract: This study reports on an analysis of the lead concentrations in 123 venous blood samples collected from Perth children aged between two months and 17 years attending Princess Margaret Hospital. The overall geometric mean was 6.9 μg lead per 100 ml whole blood, with 95 per cent of results lying between 3.2 and 14.8 μg/100 ml. Among children under five years of age, those aged between 18 months and two years had the highest geometric mean blood lead (11.1 μg/100 ml). There were no consistent associations between geometric mean blood lead and area of residence, age group or sex. In this sample of Perth children, the mean blood lead concentration was lower than those reported in other studies. Less than 0.1 per cent of children of the age range studied would have been expected to have lead levels exceeding the NHMRC ‘level of concern’ (25 μg/100 ml) current at the time of the study. However, the recent adoption of goal of less than 10 μg/100 ml could mean that lead levels in up to 21 per cent of Perth children would now be regarded as excessive.     

Declining blood lead levels in Victorian children

Abstract: To investigate the distribution of blood lead levels in a sample of Victorian children, and to compare current levels with those from a similar survey in 1979, blood was tested for lead in 252 children (123 under five years) attending Royal Children's Hospital as outpatients and having venepuncture blood samples for medical reasons. Blood lead levels were determined by graphite furnace atomic absorption spectrophotometer. The mean blood lead level was 0.26 μmol/L (5.4 μg/dL). In the under-five age group, the mean was 0.28 μmol/L (5.7 μg/dL). Only 1.6 per cent of this group exceeded the National Health and Medical Research Council action level of 0.72 μmol/L (15 μg/dL). Levels in this age group have declined significantly since 1979, when the mean was 0.54 μmol/L (11.1 μg/dL) and 12.9 per cent exceeded 0.72 μmol/L (15 μg/dL). Average blood lead levels have halved since 1979, with likely contributing factors being reduced exposure from lead in diet, reduced access to lead in paint and reduced lead in ambient air. Children with elevated levels had identifiable risk factors such as pica or exposure to lead-based paint, suggesting the need for ongoing public health action to prevent exposure in these groups.     

Determinants of Blood Lead Levels across the Menopausal Transition

In this study, the authors sought to evaluate the impact of menopause on lead remobilization from bone-lead stores. The study was conducted between 1993 and 1995 in Mexico City and included 903 women (mean age = 46.8 y [standard deviation = 8.2 y]). Participants provided information about reproductive variables and known risk factors for high PbB levels. PbB levels were determined with graphite furnace atomic absorption spectrophotometry. The authors used linear-regression models to describe the relationship between PbB levels and variables of interest. PbB levels ranged from 1.0 μg/dl to 43.8 μg/dl (mean = 11.0 μg/dl). Menopausal women at baseline had the highest PbB levels; the mean difference between pre- and postmenopausal women was 0.76 μg/dl (95% confidence interval = 0.024, 1.48). We observed an inverted U-shaped relationship between PbB level and age. The highest PbB levels were observed in women aged 47-50 y. Other important predictors of PbB levels were use of lead-glazed ceramics, number of pregnancies, history of cigarette smoking, and height. Our results support the hypothesis that bone lead may be mobilized during menopause and may constitute an important source of exposure.     

Season Modifies the Relationship between Bone and Blood Lead Levels: The Normative Aging Study

Bone serves as a repository for 75% and 90–95% of lead in children and adults, respectively. Bone lead mobilization heightens during times of increased bone turnover, such as pregnancy, lactation, hyperthyroidism, and the rapid growth of childhood. Blood lead levels show seasonal periodicity. Children demonstrate peak blood lead levels in midsummer and a secondary peak in late winter. Pregnant women demonstrate the highest mean blood lead levels in winter (January-March) and the lowest in summer (July-September). This fluctuation in blood lead levels may be related to seasonal patterns of environmental exposures, but it may also be partially related to the increased mobilization of bone lead stores during the winter months. We performed bone lead measurements using a K-x-ray fluorescent instrument to determine micrograms of lead per gram of bone mineral (parts per million) in middle-aged and elderly men who participated in the Normative Aging Study. We obtained measurements of blood and bone lead during the high sun exposure months of May-August (summer; n = 290); the intermediate sun exposure months of March, April, September, and October (spring/fall; n = 283); and the low sun exposure months of November-February (winter; n = 191). Mean blood lead concentrations were 5.8 μg/dl, 6.1 μg/dl, and 6.6 μg/dl for the summer, spring/fall, and winter, respectively. Mean patella (trabecular bone) lead concentrations were 34.3 μg/gm, 29.7 μ/gm, and 29.0 μg/gm for the summer, spring/fall, and winter time periods, respectively. In multivariate regression models, adjusted for age, smoking, alcohol ingestion, and dietary intake of iron and vitamin C, the authors found a strong interaction between season and bone lead level—with bone lead levels exerting an almost 2-fold greater influence on blood levels during the winter months than the summer months. The authors concluded that elevated blood lead levels in winter may be related to increased mobilization of endogenous bone lead stores, potentially from decreased exposure to sunlight, lower levels of activated vitamin D, and enhanced bone resorption.