Utilizing Citizen Science to Reverse the Current Lead Testing Paradigm: Development of a Scalable, Low-cost Home Lead Test Kit

Hormonal Contraception and Blood Lead Levels in Inner-City Adolescent Girls

Back to table of contents Previous article Next article Clinical & Research NewsFull AccessLead in Children's Blood May Contribute to ADHD's Hyperactivity ComponentJoan Arehart-TreichelJoan Arehart-TreichelSearch for more papers by this authorPublished Online:2 Nov 2007https://doi.org/10.1176/pn.42.21.0020aThanks to government regulation, lead poisoning in children is no longer common in the United States. However, American youngsters are still widely exposed to low levels of lead in water, soil, and other venues.But even these lower levels of lead in turn may contribute to attention-deficit/hyperactivity disorder (ADHD) in some American children, a new study suggests.The study was headed by Joel Nigg, Ph.D., a professor of clinical psychology at Michigan State University. Results are in press with Biological Psychiatry.Studies done in the 1980s have already linked the amount of lead in children's blood with ADHD. But the levels—10-20 ug/dl—were higher than the levels usually found in American children today, which average 1-2 ug/dl. So Nigg and his colleagues wanted to see whether these lower blood levels could also be associated with ADHD.The researchers recruited subjects for the study from schools, clinics, and advertisements. To obtain the broadest and most representative sample possible, the investigators advertised for both healthy children and children suspected of having or diagnosed with ADHD. A total of 845 families expressed interest in participating in the study.The children in these families were then screened extensively with various instruments—say, the Child Behavior Checklist and the Kiddie Schedule for Affective Disorders and Schizophrenia—to determine whether they had ADHD or other psychiatric disorders.One hundred-and-fifty children aged 8 to 17 were finally selected to participate in the study. A third had ADHD, combined type; a third had ADHD, predominantly inattentive type; and the remainder did not have ADHD and could thus serve as controls. Moreover, the levels of lead in the blood of all the subjects closely matched the American average of 1-2 ug/dl, with a maximum level of 3.4 ug/dl.Blood lead levels were significantly higher in the children with ADHD, combined type, than in the control children, but this was not the case in children who had ADHD, predominantly inattentive type. So Nigg and his group believe that low lead levels in the blood might play a role in the hyperactivity component of ADHD, but not in the inattention component of it.How lead might contribute to hyperactivity is not clear. It does not seem to be mediated by lead's negative impact on intelligence, because while the researchers found that blood lead levels in their subjects were correlated with IQ, they also found that IQ could not explain the link between lead and hyperactivity. Low-level lead exposure is known to disrupt mid-brain dopamine circuitry, and this circuitry, however, is involved in ADHD.Although the researchers suspect that low blood levels of lead may play a role in a number of cases of ADHD-related hyperactivity, they do not believe that this is so in all cases, because some of their subjects with mildly elevated blood levels did not have ADHD-related hyperactivity, while some of their subjects with ADHD-related hyperactivity did not have elevated blood levels of lead.The study's results have public health policy implications, Nigg told Psychiatric News, emphasizing that “prevention of lead exposure may be important at even lower levels than we thought.”The study was financed by Michigan State University and the Centers for Disease Control and Prevention.An abstract of “Low Blood Lead Levels Associated With Clinically Diagnosed Attention-Deficit/Hyperactivity Disorder and Mediated by Weak Cognitive Control” is posted at<www.journals.elsevierhealth.com//periodicals/bps> under “Articles in Press.” ▪ ISSUES NewArchived

Recent studies suggested that blood transfusion may represent a significant source of lead exposure in premature infants. Objectives of this study were to determine blood lead levels (BLLs) in a representative sample of blood donors and to identify risk factors associated with BLLs of 0.15 µmol/L or more. A study was conducted in 2006 to 2007 in 49 drive sites in Quebec. Individuals who qualified for blood donation were eligible to participate. Information was harvested from blood donor file and a standardized self-administered questionnaire. Lead analysis was performed by inductively coupled plasma mass spectrometry. Data on Quebec blood donors from 2003 to 2006 (n = 320,543) were used to establish a reference population. Geometric mean (GM) and 95% confidence interval (CI) were used to describe the results. The project was approved by an ethics committee. Of 6715 eligible individuals, 3490 participated (1392 women and 2098 men). Their mean age was 46.5 years. Results were weighted for region, sex, and age. The GM of BLLs was 0.082 µmol/L (95% CI, 0.027-0.247; range, 0.011-2.90 µmol/L). BLLs of more than 0.15 µmol/L were found in 15.5% of participants. In multivariate analysis, BLLs were mainly explained by age and sex of participants (p < 0.001). A significant association was also found between BLLs and the region of residence, education level, dwelling age, occupational and leisure activities at high risk for lead exposure, smoking, and alcohol intake (p < 0.001). BLL in blood donors is strongly explained by sex and age, a fact that can be taken into consideration when transfusing neonates.

We described elevated blood lead level (BLL; ≥ 10 μg/dL) prevalence among newly arrived refugee children in Massachusetts. We also investigated the incidence of BLL increases and BLLs newly elevated to 20 μg/dL or higher in the year following initial testing, along with associated factors. We merged data from the Massachusetts Department of Public Health's Refugee and Immigrant Health Program and the Childhood Lead Poisoning Prevention Program on 1148 refugee children younger than 7 years who arrived in Massachusetts from 2000 to 2007. Elevated BLL prevalence was 16% among newly arrived refugee children. The rate ratio for BLL elevation to 20 μg/dL or higher after arrival was 12.3 (95% confidence interval [CI] = 6.2, 24.5) compared with children in communities the state defines as high-risk for childhood lead exposure. Residence in a census tract with older housing (median year built before 1950) was associated with a higher rate of BLL increases after resettlement (hazard ratio = 1.7; 95% CI = 1.2, 2.3). Refugee children are at high risk of lead exposure before and after resettlement in Massachusetts. A national surveillance system of refugee children's BLLs following resettlement would allow more in-depth analysis.

Lead (Pb) is an inorganic chemical element (95%) commonly found in soil, rocks, and plants. The use of fuel and oil containing lead is relatively high in Indonesia. Motorcycle or machine repair shop workers are at high risk of lead exposure, especially when removing used oil. Workers are exposed to oil containing lead while removing used oil from the engine, cleaning the engine cover with gasoline, opening the oil bottle cap, and pouring oil. Even, these processes can lead to lead poisoning. This study aims to evaluate workers’ risk of lead exposure during the oil-removing process at Repair Shop X. This descriptive study used a semi-quantitative approach with a Dermal Risk Exposure Method (DREAM). This study involved a total of 5 workers at Repair Shop X in the process of removing motorcycle oil. The actual dermal exposure value reached 340.36 based on the sum of the four activities. This was considered in the very high exposure category. Meanwhile, based on the activity obtained by calculating worker hygiene and work environment. The total exposure value was 306.33, which is a very high category. Therefore, using Personal Protective Equipment (PPE) such as gloves and maintaining worker and work environment hygiene by cleaning with water regularly can help minimize lead exposure.

Nicotine pouches (NPs) are an emerging nicotine delivery system. Understanding nicotine and toxicant exposure among NP users compared with users of other tobacco products and non-users is critical for informing public health strategies. Data (n = 4527) were drawn from the Population Assessment of Tobacco and Health Study Wave 7 (2022-2023). Participants were classified into four mutually exclusive groups: non-tobacco users, exclusive NP users, exclusive e-cigarette users, and exclusive cigarette smokers. Geometric mean concentrations of biomarkers from urinary nicotine metabolites, minor tobacco alkaloids, and heavy metals were compared across groups using general linear model adjusted for demographics and current marijuana use. Despite having higher levels of nicotine metabolites than non-tobacco users (eg, cotinine, 2137.2 vs. 0.2ng/mg creatinine, p< .0001), exclusive NP users showed no significant differences in levels of metals or minor tobacco alkaloids (p > .05). Exclusive NP users had comparable levels of nicotine metabolites to exclusive cigarette smokers (p > .05), but significantly higher concentrations of certain nicotine metabolites than exclusive e-cigarette users (eg, TNE-2: 27.3 vs. 7.0, p= .02). Meanwhile, exclusive NP users exhibited lower levels of anabasine (0.6 vs. 9.3ng/mg creatinine, p< .0001), anatabine (0.4 vs. 14.7ng/mg creatinine, p< .0001), and lead (0.2 vs. 0.4ng/mg creatinine, p= .003) than exclusive cigarette smokers and lower levels of lead (p= .02) than exclusive e-cigarette users. NP users have substantially elevated nicotine exposure without a corresponding rise in selected tobacco alkaloids or metals. Findings from objective biomarker measures could inform harm reduction strategies and shape regulatory policies concerning emerging nicotine products. Nicotine pouches (NPs) are gaining popularity in the United States. The long-term health effects of nicotine pouch use remain unknown, and this national study offered early evidence into the scope of toxicant exposure associated with nicotine pouch use. Exclusive nicotine pouch users exhibited higher levels of nicotine metabolites but lower concentrations of anabasine and lead compared to cigarette smokers, indicating that NPs may serve as a potential harm-reduction strategy for combustible cigarette smokers. Findings from this study add to the current field of tobacco regulatory science and may inform future efforts to evaluate their effectiveness in smoking cessation or substitution.

ObjectivesThis study aimed to document the trend in blood lead levels in Korean lead workers from 2003 until 2011 and blood lead levels within each of the main industries.MethodsNine years (2003–2011) of blood lead level data measured during a special health examination of Korean lead workers and collected by the Korea Occupational Safety and Health Agency were analyzed. Blood lead levels were determined by year, and a geometric mean (GM) was calculated for each industry division.ResultsThe overall GM blood lead level for all years combined (n = 365,331) was 4.35 μg/dL. The GM blood lead level decreased from 5.89 μg/dL in 2003 to 3.53 μg/dL in 2011. The proportion of the results ≥30 μg/dL decreased from 4.3% in 2003 to 0.8% in 2011. In the “Manufacture of Electrical Equipment” division, the GM blood lead level was 7.80 μg/dL, which was the highest among the industry divisions. The GM blood lead levels were 7.35 μg/dL and 6.77 μg/dL in the “Manufacturers of Rubber and Plastic Products” and the “Manufacture of Basic Metal Products” division, respectively.ConclusionsThe blood lead levels in Korean lead workers decreased from 2003 to 2011 and were similar to those in the US and UK. Moreover, workers in industries conventionally considered to have a high risk of lead exposure also tended to have relatively high blood lead levels compared to those in other industries.

The blood lead reference value (BLRV) is used for guiding lead prevention and control measures. It is usually defined as the 97.5th percentile of the population-based blood lead level in each country. This study aims to determine the BLRV and factors associated with elevated (≥5 µg/dL) blood lead levels among children aged 1–5 years in Thailand. A cross-sectional study was conducted using secondary data extracted from a national survey, implemented in 171 hospitals during October 2018–September 2019. Demographic characteristics and potential risk factors including lead-related industries were collected. Multilevel logistic regression was used. Of 3,184 children included in the survey, the BLRV was 6.9 µg/dL. Three significant risk factors were identified: living near a lead factory (adjusted odds ratio (AOR) 2.09, 95% CI 1.27–3.42), exposure to the manufacture of fishing tackle (AOR 4.39, 95% CI 1.54–12.50), and exposure to the manufacture of shot and ammunition (AOR 6.30, 95% CI 1.81–21.93). Despite a calculated BLRV of 6.9 µg/dL, we propose a BLRV of 5 μg/dL in Thailand based on guidelines from the United Kingdom. Surveillance of blood lead levels should be established among children at high risk of lead exposure.

Maternal nutritional status during pregnancy and surma use determine cord lead levels in Karachi, Pakistan

Lead poisoning is an emerging worldwide public health concern, especially in the developing countries. Occupational tasks such as spray painting and welding in informal automobile repair enterprises present risks of exposures to lead generally through inhalation and ingestion. The artisans therefore risk high blood lead (BPb) levels, which is critical to chronic adverse health effects of lead. The study aimed at assessing the influence of occupational tasks on personal airborne lead exposures and to evaluate the association between these exposures with blood lead (BPb) levels among the artisans. A cross-sectional study was conducted in ten informal automobile repair workshops. Task-specific personal inhalable air samples and blood samples were collected concurrently for 20 participants performing five distinct occupational tasks. Lead levels were analysed using inductively coupled plasma atomic emission spectroscopy and data analysed by analysis of variance, simple and multiple linear regressions. The results indicated significant differences in airborne lead (PbA) exposure levels in different occupational tasks (p = 0.000). Lead-acid battery repairs recorded mean PbA exposure level of [76.11 ± (10.81 SE) µg/m3] exceeding the WHO 50µg/m3 airborne lead permissible exposure limit. The average (PbA) exposure level was 22.55 ± (5.05 SE) µg/m3, while the mean (BPb) level was 25.08 ± (3.48 SE) µg/dl. A significant positive correlation between task-based airborne lead with blood lead levels was observed (r = 0.68, p = 0.001). In conclusion, the occupational tasks influenced personal airborne lead exposure levels, which in turn was an important predictor of blood lead levels. The study recommends lead exposure assessments, medical screening and intervention measures to minimize the risk and consequences of occupational exposures to lead among the study population.

The first pediatric lead screening typically occurs at 1-year well-child care visits. However, data on the extent of maternal lead exposure and its long-term consequences for child health are lacking. To investigate the associations between maternal red blood cell (RBC) lead levels and intergenerational risk of overweight or obesity (OWO) and whether adequate maternal folate status is associated with a reduction in OWO risk. Prospective birth cohort study. The analysis was conducted from July 14, 2018, to August 2, 2019, at Johns Hopkins Bloomberg School of Public Health. This study included 1442 mother-child pairs recruited at birth from October 27, 2002, to October 10, 2013, and followed up prospectively at Boston Medical Center. Child body mass index (BMI) z score, calculated according to US national reference data, and OWO, defined as BMI at or exceeding the 85th percentile for age and sex. Maternal RBC lead levels and plasma folate levels were measured in samples obtained 24 to 72 hours after delivery; child whole-blood lead level was obtained from the first pediatric lead screening. The mean (SD) age of mothers and children was 28.6 (6.5) years and 8.1 (3.1) years, respectively; 50.1% of children were boys. The median maternal RBC lead level and plasma folate level were 2.5 (interquartile range [IQR], 1.7-3.8) μg/dL and 32.2 (IQR, 22.1-44.4) nmol/L, respectively. The median child whole-blood lead level and child BMI z score were 1.4 (IQR, 1.4-2.0) μg/dL and 0.78 (IQR, -0.08 to 1.71), respectively. Maternal RBC lead level was associated with child OWO risk in a dose-response fashion, with an odds ratio (OR) of 1.65 (95% CI, 1.18-2.32) for high maternal RBC lead level (≥5.0 μg/dL) compared with low maternal RBC lead level (<2.0 μg/dL). Child OWO was highest among children of OWO mothers with high RBC lead levels (adjusted OR, 4.24; 95% CI, 2.64-6.82) compared with children of non-OWO mothers with low RBC lead levels. Children of OWO mothers with high RBC lead levels had 41% lower OWO risk (OR, 0.59; 95% CI, 0.36-0.95; P = .03) if their mothers had adequate plasma folate levels (≥20.4 nmol/L) compared with their counterparts. In this sample of a US urban population, findings suggest that maternal elevated lead exposure was associated with increased risk of intergenerational OWO independent of postnatal blood lead levels. Adequate maternal folate status appeared to be associated with lower OWO risk. If confirmed by additional studies, these findings have implications for prenatal lead screening and management to minimize adverse health consequences on children.

Recent literature has shown that analyzing newborn dried blood spots (DBS) may be effective in assessing some prenatal environmental exposures, such as exposure to lead. The purpose of this study was to evaluate the relationship between prenatal exposure to lead (as measured by newborn DBS results) and blood lead levels (BLLs) in infants 6 months of age or younger, using public health registry data for infants born in Texas from July 2002 through July 2006. The Texas Child Lead Registry (TCLR) was used to identify infants with documented elevated BLLs of 10 μg/dL or higher as well as infants with documented low BLLs. BLLs for these children were compared to their corresponding newborn DBS results using Pearson correlation coefficients and exact logistic regression models. Overall, a significant but weak positive correlation was found between infant BLLs and corresponding newborn DBS lead levels (r = 0.48). However, the odds of an infant with an elevated newborn DBS lead level having an elevated BLL at 6 months of age or younger were much greater than for an infant with a low newborn DBS lead level of <5 μg/dL (adjusted odds ratio 27.95, 95% CI: 5.52-277.28). Although an association was observed between newborn DBS lead levels and BLLs in infants tested between 0 to 6 months of age, our findings suggest that prenatal exposure may not be the only significant source of lead exposure for infants ≤6 months of age.

Very low maternal lead level in pregnancy and birth outcomes in an eastern Massachusetts population

To evaluate occupational exposures to lead in shipfitters cutting and riveting lead-painted iron plates aboard an iron-hulled sailing vessel, we conducted an environmental and medical survey. Lead exposures in seven personal (breathing zone) air samples ranged from 108 to 500 micrograms/m3 (mean 257 micrograms/m3); all were above the Occupational Safety and Health Administration (OSHA) standard of 50 micrograms/m3. In two short-term air samples obtained while exhaust ventilation was temporarily disconnected, mean lead exposure rose to 547 micrograms/m3. Blood lead levels in ten shipfitters ranged from 25 to 53 micrograms/dl (mean, 37.8 micrograms/dl); levels in three of these workers exceeded the upper normal limit of 40 micrograms/dl. Blood lead levels in shipfitters were significantly higher than in other shipyard workers (mean 10.0 micrograms/dl; p less than 0.001). Smoking shipfitters (mean, 47 micrograms/dl) had significantly higher lead levels than nonsmokers (mean, 32 micrograms/dl; p = 0.03). Lead levels in shipfitters who wore respirators were not lower than in those who wore no protective gear (p = 0.68). Four shipfitters had erythrocyte protoporphyrin (EP) concentrations above the adult upper normal limit of 50 micrograms/dl. A close correlation was found between blood lead and EP levels (r = 0.70). Prevalence of lead-related symptoms was no higher in shipfitters than in other workers. No cases of symptomatic lead poisoning were noted. These data indicate that serious occupational exposure to lead can occur in a relatively small boatyard.

Low level lead (Pb) exposure during gestation and lactation: assessment of effects on pubertal development in Fisher 344 and Sprague-Dawley female rats