Median Lead Concentration Research Articles

Lead in umbilical cord blood and associated factors in Casablanca Morocco: A preliminary results

BackgroundLead is the most common toxic metal to which Moroccans are exposed. Given the susceptibility of the fetus to lead, it is crucial to assess prenatal lead exposure. However, in Morocco, no study has assessed prenatal exposure to lead. The main goals of the present study are to determine lead concentration in umbilical cord blood and identify risk factors for prenatal lead exposure in Casablanca, Morocco. MethodsTo achieve these purposes, 87 cord blood lead samples were collected from mothers-baby pairs from January to December 2019. Indeed, a structured questionnaire was used to collect socio-demographic characteristics, obstetric data, leisure, cultural habits, and environmental information. Cord blood lead level was analyzed by inductively coupled plasma-mass spectrometry. ResultsThe median lead concentration was 4.902 µg/dl with a minimum and maximum of 0.833 µg/dl and 23.593 µg/dl, respectively. A high proportion of the newborns (65.52 %) had cord blood lead levels above the Centers for Disease Control (CDC) allowable threshold limit (3.5 µg/dl). Statistical analysis was performed to assess the association between blood levels and the above factors. Lead levels in cord blood were significantly associated with the maternal educational level, anemia history, delivery mode, passive smoking during pregnancy as well as with the frequency of consumption of tea. ConclusionThis study provides the first data on lead levels in newborns. Cord blood lead levels were high in the majority of the participants, these results reinforce the need to establish health surveillance programs in Morocco.

Assessment of Lead in Drinking Water from Multiple Drinking Water Sampling Programs for a Midsize City.

Following an exceedance of the lead action level for drinking water in 2016, the Pittsburgh Water and Sewer Authority (PWSA) undertook two sampling programs: the required biannual Lead and Copper Rule (LCR) compliance testing and a home sampling program based on customer requests. The LCR sampling results, at locations expected to be elevated when corrosion is not well controlled, had higher concentrations than customer-requested homes, with 90th percentile values for the LCR sites exceeding the action level through 2019 (except for June 2018). Customer-requested concentrations showed greater variability, with the median lead concentration for customer-requested samples below detection for each year of sampling, suggesting only some homes show elevated lead when corrosion control is not fully effective. Corrosion control adjustments brought the utility back into compliance in 2020 (LCR 90th percentile of 5.1 ppb in June 2020); customer-requested sampling after the addition of orthophosphate indicated below detection levels for 59% of samples. Monte Carlo simulations indicate LCR samples do not all represent high lead risk sites, and the application of corrosion control more significantly affects higher lead concentration sites. Broader water quality sampling provides information about specific homes but is not well suited to assessing the efficacy of corrosion control efforts by utilities.

Antlers of European roe deer (Capreolus capreolus) as monitoring units to assess lead pollution in a floodplain contaminated by historical metal ore mining, processing, and smelting in the Harz Mountains, Germany

Lead concentrations in hard antlers of adult European roebucks (Capreolus capreolus) were analyzed to assess lead exposure of roe deer roaming the floodplain of the Innerste River, a river system contaminated due to historical metal ore mining, processing, and smelting in its upper reaches. Antler lead concentrations of roebucks culled in the period 1939–2018 within or close to the Innerste floodplain ranged between <0.17 mg Pb/kg (limit of detection) and 51.5 mg Pb/kg (air-dry weight). Median lead concentration in antlers of roebucks culled within the floodplain was 11.1 mg Pb/kg, compared to 2.3 mg Pb/kg in antlers of bucks culled in the floodplain vicinity (P < 0.01). Sampling year had no significant effect on antler lead concentrations (P = 0.748). Lead isotope ratios of antlers from the Innerste downstream area (206Pb/207Pb: 1.179–1.181; 208Pb/206Pb: 2.083–2.085) fell within the range of those reported for hydrothermal vein deposits from the upper catchment area of the Innerste River in the Harz Mountains. Our study demonstrates the long-lasting impact of the historical metal ore mining, processing, and smelting in the Harz Mountains on lead pollution in floodplains of rivers draining this area and the lead exposure of wild herbivores inhabiting the floodplains. Furthermore, it highlights the suitability of roe deer antlers for monitoring environmental lead levels and the usefulness of lead isotope signatures in antlers for source apportionment of lead pollution.

Lead concentrations in antlers of European roe deer (Capreolus capreolus) from an agricultural area in Northern Germany over a 119-year period\u2014a historical biomonitoring study

We analyzed the lead content in antlers of 90 adult European roe bucks (Capreolus capreolus) that had been culled between 1901 and 2019 in an agricultural-dominated hunting district in Lower Saxony (Northern Germany). Antler lead values ranged between 0.2 and 10.9 mg/kg dry weight. Median lead concentration was highest after World War II, during a period (1956–1984) of rapidly increasing mass motorization and use of leaded gasoline. Lead levels in antlers decreased markedly after the phase-out of leaded gasoline, but high values were still found in some recently collected antlers. This could indicate persistent lead pollution from former use of lead additives to gasoline, other traffic-related sources, or from agricultural sources (e.g., sewage sludge, fertilizers). This study highlights the suitability of analyzing roe deer antlers for the historical monitoring of changing lead levels in the environment. By collecting antlers and providing them for study, local hunters can significantly contribute to environmental surveillance and the monitoring of environmental pollution by bone-seeking contaminants.

Lead concentrations in breast milk of Moroccan nursing mothers and associated factors of exposure: CONTAMILK STUDY

The aim of CONTAMILK study was to estimate levels of contamination of breast milk (BM) of Moroccan nursing mothers by some xenobiotics including, lead (Pb), to identify associated factors of exposure and to determine the daily intake of newborns. Lead concentrations were determined in 70 samples of colostrum by ICPMS and a structured questionnaire was filled during milk collection to report participants’ data. The median lead concentration was 908 μg/L (range 1.38–515,39 μg/L) and in 79 % of samples, levels were higher than the normal range reported by the World Health Organization (WHO) in BM (2−5 μg/L). Indeed, preterm delivery, frequency of use of cosmetic powders and lipsticks were significantly associated with the level of lead in BM. The estimated daily intake was greater than the tolerable daily intake (TDI) of the European food safety authority (0.5 μg/kg/day) for 39 babies and 6 babies according to the WHO (3.6 μg/kg/day).

Lead contamination in tissues of large avian scavengers in south-central Europe.

Lead poisoning from spent ammunition is known to affect many avian species. Birds of prey ingest lead when feeding on game shot with lead gunshot or bullets. Raptors with scavenging habits are particularly vulnerable to ingesting lead in areas with intensive hunting and are good indicators of the risk of poisoning from lead ammunition. To assess how much facultative and obligate avian scavengers suffer lead contamination in south-central Europe, between 2005 and 2019 we collected and analysed 595 tissue samples from 252 carcasses of 4 species (golden eagle, bearded vulture, griffon vulture, cinereous vulture). Lead concentrations in organs showed a similar pattern across species with long and small bones revealing the highest median values (5.56 and 6.8mg/kg w.w., respectively), the brain the lowest (0.12), and the liver and kidney the intermediate (0.47 and 0.284). Overall, 111 individuals (44.0%) had lead concentrations above background thresholds in at least one tissue (i.e. >2mg/kg w.w. in soft tissues, >8.33 in bone) and 66 (26.2%) had values indicating clinical poisoning (>6mg/kg w.w. in liver, >4 in kidney, >16.6 in bone). Tissue lead concentrations and incidence of clinical and sub-clinical poisoning were higher in golden eagles and griffon vultures than in bearded and cinereous vultures, likely due to different feeding habits. In all species we found a rapid increase in lead values with age, but differences between age classes were significant only in the golden eagle. Birds with lead fragments in their digestive tract, as detected by X-rays, had higher median lead concentrations, suggesting that hunting ammunition is the main source of lead poisoning. Our results imply that lead impacts the demography of these long-lived species with delayed sexual maturity and low reproduction rate. A rapid transition towards lead-free bullets and gunshot is therefore required across Europe.

Elevated Levels of Lead (Pb) Identified in Georgian Spices.

Background:Human lead (Pb) exposure can result in a number of adverse health outcomes, particularly in children.Objective:An assessment of lead exposure sources was carried out in the Republic of Georgia following a nationally representative survey that found elevated blood lead levels (BLLs) in children.Methods:A range of environmental media were assessed in 25 homes and four bazaars spanning five regions. In total, 682 portable X-Ray Fluorescence measurements were taken, including those from cookware (n = 53); paint (n = 207); soil (n = 91); spices (n = 128); toys (n = 78); and other media (n = 125). In addition, 61 dust wipes and 15 water samples were collected and analyzed.Findings:Exceptionally high lead concentrations were identified in multiple spices. Median lead concentrations in six elevated spices ranged from 4–2,418 times acceptable levels. Median lead concentrations of all other media were within internationally accepted guidelines. The issue appeared to be regional in nature, with western Georgia being the most highly affected. Homes located in Adjara and Guria were 14 times more likely to have lead-adulterated spices than homes in other regions.Conclusions:Further study is required to determine the source of lead contamination in spices. Policy changes are recommended to mitigate potential health impacts. The results of this study contribute to a growing body of evidence that points to adulterated spices as a significant source of human lead exposure.

Risk Assessment of Lead Exposure from Cervid Meat in Norwegian Consumers and in Hunting Dogs

Risk Assessment of Lead Exposure from Cervid Meat in Norwegian Consumers and in Hunting Dogs

Lead concentrations in the blood and eggs of backyard laying hens

AIMS: To investigate the prevalence of lead exposure in hens and eggs from backyard poultry in a sample of Auckland households, the relationship between concentrations of lead in the blood of the hens and in the shells and yolks of eggs from the same household, and to examine associations with measures of hen health, environment and husbandry factors.METHODS: Thirty households participated in the study from August to November 2016, each providing one adult hen for sampling, an egg from the household if available, and completing a questionnaire on hen husbandry. Concentrations of lead in blood were determined using a portable lead analyser. Eggs were analysed for concentrations of lead in the yolk and shell using inductively coupled plasma mass spectrometry after biological digestion with a mixture of nitric and hydrochloric acid.RESULTS: Twenty three of 30 hens (77%) showed evidence of lead exposure, with median concentrations of lead in blood of 0.77 (min <0.16, max 8.02) μmol/L. All eggs showed evidence of lead exposure, with concentrations of lead in the yolk ranging from 0.003–1.07 mg/kg, and concentrations of lead in the eggshell ranging from <0.1–0.82 mg/kg. A positive correlation existed between concentrations of lead in the blood of a hen and concentrations of lead in egg yolk from the same hen (R2=0.97), and both the yolk (R2=0.58) and shell (R2=0.30) of an egg from her flock. No association was found between concentrations of lead in blood and hen health indices measured in this study. Concentrations of lead in blood were higher in hens from properties with homes built before 1941 than between 1941–1960 (p=0.03), and in hens from properties with weatherboard homes than brick homes (p=0.049).CONCLUSIONS AND CLINICAL RELEVANCE: There was a high prevalence of lead exposure in this sample of Auckland backyard chickens, with the majority of hens being sub-clinically affected. Associations were found between concentrations of lead in the blood of the hens, and properties with homes built before 1941 and clad in weatherboard. Concentrations of lead in over half the egg yolks sampled were at levels sufficient to warrant human health concern. The assessment of concentrations of lead in backyard poultry and eggs intended for human consumption is recommended to protect human and bird health.

Comparison of lead levels in edible parts of red deer hunted with lead or non-lead ammunition

Game meat may contain elevated concentrations of lead especially if lead-containing ammunition is used for hunting. Then a health risk is possible for consumer groups with high game meat intake.The lead concentrations in three edible parts (marketable meat from the area close to the wound channel, saddle and haunch) of meat from red deer (Cervus elaphus) between animals hunted either with lead or non‑lead ammunition were compared. Furthermore, lead levels in game meat of lead-shot red deer were compared with those of lead-shot roe deer and lead-shot wild boar.Ninety red deer were shot and killed in the context of this study (64 with lead and 26 with non‑lead ammunition). Since the lead concentration for a number of the samples was below the limit of detection or the limit of quantification, statistical methods for left-censored data were applied.The median concentrations of lead in game meat did not differ significantly between lead shot and non‑lead shot animals. However, when we analyzed the more elevated lead concentrations, they were significantly higher in edible parts of animals shot with lead ammunition than non-lead ammunition. The highest concentrations were found in samples from edible meat from the area close to the wound channel (max 3442 mg Pb/kg), followed by the saddle (max 1.14 mg Pb/kg) and with the lowest levels in the haunch (max 0.09 mg Pb/kg). A comparison of game species revealed that the lead concentration in haunch and saddle of lead shot red deer was higher than in the corresponding samples of lead shot roe deer.Our results have shown that by the use of non-lead ammunition, a significant reduction of the lead concentration especially in edible parts near the wound channel is possible.

Lead in breastmilk samples from women living in the West Bank: a cross-sectional study

BackgroundBreastmilk is the recommended form of enteral nutrition for all infants. Infants nourishing on breastmilk contaminated with lead are at high risk of exposure to this neurotoxic heavy metal. The aim of this study was to screen lead concentrations in samples of breastmilk obtained from women living in three main regions of the West Bank and to investigate the sociodemographic characteristics associated with high lead concentrations. MethodsIn this cross-sectional study, breastmilk samples were collected from breastfeeding women living in Nablus, Ramallah, and Jerusalem. The participants' sociodemographic characteristics were recorded, and the lead concentration in breastmilk samples were quantified using a graphite furnace atomic absorption spectrophotometer. Ethical approval was obtained from the Institutional Review Board of An-Najah National University, and all participants provided written informed consent. FindingsBreastmilk samples were obtained from 89 women. The median lead concentration was 4 μg/L (range 2–12 μg/L). The lead concentration was higher than WHO's safety limits for occupationally unexposed population in 17 (19%) samples. Lead concentrations were also significantly higher in samples obtained from women living in refugee camps and cities (p=0·003) than in women living in villages, higher in women with low monthly household income than in women with high monthly household (p=0·020), higher in women living in houses with peeling paint than in women living in houses with no peeling paint (p=0·026), higher in women who worked in agriculture for more than 3 years than in women who worked in agriculture for less than 3 years or less (p=0·005), and higher in women who frequently used eye kohl than in women who did not (p=0·004). Multiple linear regression analysis showed that using eye kohl was a significant predictor (p=0·040) of lead concentration in breastmilk above WHO's safety limits. InterpretationIn this study, about one-fifth of women had concentrations of lead in their breastmilk above the WHO's safety limits. Authorities need to implement measures to eliminate or reduce lead exposure, especially in refugee camps and cities. Eye kohl preparations marketed in the occupied Palestinian territory should be screened for lead content. FundingNone.

Australian atmospheric lead deposition reconstructed using lead concentrations and isotopic compositions of archival lichen and fungi

Lead concentrations and their isotopic compositions were measured in lichen genera Cladonia and Usnea and fungi genus Trametes from the Greater Sydney region (New South Wales, Australia) that had been collected and archived over the past 120 years. The median lead concentrations were elevated in lichens and fungi prior to the introduction of leaded petrol (Cladonia 12.5 mg/kg; Usnea 15.6 mg/kg; Trametes 1.85 mg/kg) corresponding to early industrial development. During the period of leaded petrol use in Australian automobiles from 1932 to 2002, total median lead concentrations rose: Cladonia 18.8 mg/kg; Usnea 21.5 mg/kg; Trametes 4.3 mg/kg. Following the cessation of leaded petrol use, median total lead concentrations decreased sharply in the 2000s: Cladonia 4.8 mg/kg; Usnea 1.7 mg/kg. The lichen and fungi isotopic compositions reveal a significant decrease in 206Pb/207Pb ratios from the end of 19th century to the 1970s. The following decades were characterised by lower allowable levels of lead additive in fuel and the introduction of unleaded petrol in 1985. The environmental response to these regulatory changes was that lichen and fungi 206Pb/207Pb ratios increased, particularly from 1995 onwards. Although the lead isotope ratios of lichens continued to increase in the 2000s they do not return to pre-leaded petrol values. This demonstrates that historic leaded petrol emissions, inter alia other sources, remain a persistent source of anthropogenic contamination in the Greater Sydney region.

Environmental exposure to lead induces oxidative stress and modulates the function of the antioxidant defense system and the immune system in the semen of males with normal semen profile

We investigated the associations between environmental exposure to lead and a repertoire of cytokines in seminal plasma of males with normal semen profile according to the WHO criteria. Based on the median lead concentration in seminal plasma, 65 samples were divided into two groups: low (LE) and high exposure to lead (HE). Differences in semen volume and the pH, count, motility and morphology of sperm cells were not observed between the examined groups. The total oxidant status value and the level of protein sulfhydryl groups as well as the activities of manganese superoxide dismutase and catalase were significantly higher in the HE group, whereas the total antioxidant capacity value and the activities of glutathione reductase and glutathione-S-transferase were depressed. IL-7, IL-10, IL-12, and TNF-α levels were significantly higher in the HE group compared with the LE group. Environmental exposure to lead is sufficient to induce oxidative stress in seminal plasma and to modulate antioxidant defense system.

Workers’ dermal and total exposure to metals in biomass-fired power plants

AbstractThe aim of this study was to measure ash removal and maintenance workers’ exposure to metals, and assess the suitability of different methods to evaluate metal exposure during these work tasks. Whole-body samples and hand-washing method were used in workers’ dermal exposure assessment, and biomonitoring methods of metals in total exposure assessment. The greatest levels of Al, Pb, Cd, Cu, S, and Zn on workers’ hands were measured in recycled fuel-fired power plants. The median concentrations of lead on workers’ whole-body samples were 4.5 ng/cm2, 17.0 ng/cm2, 11.3 ng/cm2, and 58.4 ng/cm2 in pellet-, peat-, wood- and recycled fuel-fired power plants, respectively. In recycled fuel-fired power plants, workers’ excretions of Al, Pb, and Mn exceeded the reference values of non-exposed population in 33%, 100%, and 50% of samples, respectively. The dermal exposure results clearly showed that power plant ash can significantly contaminate workers’ hands and bodies. The fact that the workers’ urinary excretions of metals exceeded the reference values proved intake of metals during these work tasks. Biomonitoring methods take into account exposures from different sources and, due to that, they are the most recommended approach for estimating the total metal exposure of workers. Hand-washing and whole body sampling were the most recommendable methods for assessing the protection efficiency of gloves and coveralls.

Advanced receptor modeling of near–real–time, ambient PM2.5 and its associated components collected at an urban–industrial site in Toronto, Ontario

PM2.5 and other atmospheric pollutants were continuously monitored at high time resolution for 1 year at an urban–industrial location in Toronto, ON, Canada's largest city. The data collected for these pollutants were examined to determine seasonal trends and potential sources. Advanced receptor models including residence time weighted concentration (RTWC) and simplified quantitative transport bias analysis (sQTBA) trajectory ensemble models (TEM) and conditional probability function (CPF) were applied to these data to identify potential local and regional sources of pollution impacting this receptor site. Seasonal trends showed that concentrations of PM2.5 were more frequently high in winter than in any other season. Median concentrations of lead and arsenic were highest in fall while median levels of chromium were not significantly different over the four seasons. The black carbon–derived measurement commonly known as Delta C (i.e., BC370nm–BC880nm) had its greatest abundance in winter and lowest levels in summer. The seasonality of Delta C is indicative of the impact of residential wood combustion near the receptor site. CPF indicated that lead and iron had the most unidirectional radial plots with sectors located west–southwest of the receptor being the most likely local source regions. Winter CPF for Delta C is almost of equal strengths in all directions suggestive of near–uniform isotropic local impacts. The sQTBA model provided the most satisfactory spatial representation of impacting sources. The strongest sources of PM2.5 identified by the sQTBA model were both local and transboundary in origin. More potential source regions were found in winter and summer than in spring and fall.

Cadmium, lead and mercury concentrations in selected red deer (Cervus elaphus L.) tissues from north-eastern Croatia

Concentrations of cadmium, lead and mercury were determined in muscle, liver and kidney tissue from three different age groups of red deer (young animals aged 6 or 7 months, middle-aged animals aged 3 to 5 years, old animals aged over 8 years) from the Baranja region of Croatia. Median cadmium concentrations were low in the muscles of all investigated age groups (0.0002; 0.0009 and 0.0020 μg/g), higher in the liver (0.0279; 0.0656 and 0.1463 μg/g) and highest in the kidneys (0.4792; 2.8531 and 6.1657 μg/g). A positive correlation was established between cadmium concentration and age. In all analyzed tissues the median lead concentration was higher in young (muscle 0.0024; liver 0.0364 and kidney 0.0618 μg/g), compared to middle-aged animals (muscle 0.0001; liver 0.0184 and kidney 0.0160 μg/g). In contrast to cadmium, mercury had a negative correlation to age but median concentrations were very low (in muscle: 0.0011; 0.0001 and 0.0006 μg/g; in liver: 0.0051; 0.0037 and 0.0022 μg/g and in kidney: 0.0145; 0.0183 and 0.0106 μg/g) especially compared to cadmium. From the hygienic point of view all the examined tissues are edible since concentrations of the analyzed metals do not exceed values proposed by the official regulations, with the exception of a few kidney samples, which contained cadmium above the recommended value. Furthermore, mercury concentrations are no longer (since 2008) a matter of legislation.

Lead levels in new residential enamel paints in Taipei, Taiwan and comparison with those in mainland China

Five brands of new enamel household paints from Taiwan were analyzed: two multi-nationals and three local. The median lead concentration of 2574 parts per million (ppm) dry weight was more than 30 times the current US standard of 90 ppm for new paints and was more than 4 times the former standard of 600 ppm. Lead levels ranged from below detection (4.5 ppm) to 158,000 ppm. Lead concentrations varied significantly by color of paint and paint brand but not by price per liter. Fifty-six percent of Taiwan paints had lead levels above the 90 ppm US limit. One of the multi-national brands and two of the local brands had high levels of lead with the averages ranging from 12,890 to 53,640 ppm. Concentrations were less than 90 ppm in each of the samples from the other two brands. One of the two multi-national paint brands was imported as the house brand for its big box store in Taipei and had lead levels above 600 ppm in four of five samples. Comparison of the lead concentrations of paints from Taiwan with those that we previously analyzed from mainland China revealed higher levels in Taiwan where the median level was 2574 ppm compared to 46 ppm in mainland China.

Lead levels in milk and blood from donors to the Breast Milk Bank in Southern Brazil

Brazilian scientific literature on the adverse effects of lead on the general population is still very limited. Lead, a potentially toxic substance, has become a public health problem due to its effects, mainly those affecting the central nervous system and on the synthesis of heme. The aim of this study is to evaluate the level of lead exposure of donors to the Breast Milk Bank in the city of Londrina, Parana, by estimating the levels of that metal in milk and blood samples. This is a cross-sectional study conducted during the period between January and July 2007. All mothers enrolled as donors in the Breast Milk Bank were included in this study. A total of 92 volunteers presenting the following inclusion criteria were evaluated in the project: volunteers who were healthy, without any chronic disease, full-term pregnancy, breastfeeding between the 15th and 210 th day after giving birth, and living in the city of the study. Lead in milk and blood was quantified using the inductive coupled plasma mass spectroscopy (ICP-MS) technique. All mothers signed a consent form approved by the Research Ethics Committee from Londrina State University. The median lead concentration in milk samples was 3.0 microg/L, varying from 1.0 to 8.0 microg/L. The median of lead in blood was of 2.7 microg/dl, varying from 1.0 to 5.5 microg/dl. In Spearman correlation analysis, significant but modest correlations could be observed between the concentration of lead in blood and in milk (r(s)=0.207, p=0.048), hemoglobin and ALAD activity (r(s)=-0.264, p=0.011), level of lead in blood and mother's age (r(s)=0.227, p=0.029). However, for hematocrit and hemoglobin, the correlation was higher (r(s)=0.837, p<0.001). No statistically significant associations were found between concentrations of lead in milk and blood and demographic variables studied, obtained through interviews and validated questionnaire. The mean of milk/blood lead ratio was equal to 0.11. In general, the values found in the present study are similar to those obtained in populations in other countries, and are within background levels.

Lead in Lake Michigan and Green Bay surficial sediments

Sediment samples were collected in 1987–1990 from Green Bay and in 1994–1996 from Lake Michigan. Surficial sediments (0–1 cm) from both locations were analyzed for lead for the purpose of describing the horizontal variation of lead in 1994–1996 Lake Michigan and 1987–1990 Green Bay sediments, estimating lead fluxes to surficial sediments, and comparing results to earlier studies. With Lake Michigan concentrations ranging from below the method detection limit to 180 μg/g, the surficial sediments had mean and median lead concentrations of 70 μg/g and 64 μg/g, respectively. Lead concentrations in Green Bay surficial sediments were similar to those in Lake Michigan and ranged between the method detection limit and 160 μg/g. For the bay, mean and median concentrations were 58 and 59 μg/g, respectively. Surficial lead concentrations were highest in the Southern, Waukegan, and Grand Haven basins of Lake Michigan and in the central region of Green Bay in the vicinity of Chambers Island. For Lake Michigan and Green Bay, dated sediment cores illustrate the decline in lead concentrations during the last 30 and 10 years, respectively. Lead fluxes ranged between < 0.049 and 7.2 μg/cm 2/yr for Green Bay and between 0.47 and 20 μg/cm 2/yr for Lake Michigan. Lead fluxes to Lake Michigan were lower than those reported for 1972. These are the most comprehensive fluxes of lead to Lake Michigan and Green Bay surficial sediments reported to date.

Lead-based paint on playground equipment in public children's parks in Johannesburg, Tshwane and Ekurhuleni.

To determine the use of lead-based paint in public playgrounds in the municipalities of Johannesburg, Tshwane and Ekurhuleni. Forty-nine public parks were selected from the municipalities of Johannesburg, Tshwane and Ekurhuleni. Lead levels in paint on playground equipment were measured in situ using a hand-held Thermo Scientific NITON XLP 700 Series X-ray fluorescence (XRF) analyser. Playground lead levels ranged from 'too low to detect' to 10.4 mg/cm2. The mean and median lead concentrations were 1.9 mg/cm2 and 0.9 mg/cm2 respectively. Forty-eight per cent of lead paint measurements exceeded the internationally accepted reference level of 1 mg/cm2. The study shows that lead-based paint is widely used in public playgrounds in the three study municipalities, and most likely throughout South Africa. We suggest key actions to ensure that children's playgrounds in South Africa are lead-free zones, and that childhood lead exposure in these settings is prevented.