Occupational and environmental human lead exposure in Brazil

Forecasting of secondary lead recovery from motorcycle batteries in Brazil: a contribution to waste management

This study aims to predict the potential for secondary lead recovery from motorcycle batteries in Brazil, since this is considered the second largest category of automobiles in the country. To achieve this objective, a forecasting model based on the ARIMA methodology was applied, with input data taken from Brazilian sectorial platforms. Furthermore, an analysis of the data, of the residuals, autocorrelation tests, as well as Kolmogorov-Smirnov and Dickey-Fuller tests, were performed. The SARIMA model (3,1,0) (2,0,0)12 presented a better adaptation to the behavior of the series. The results showed that the amount of secondary lead obtained based on the forecast model will be 89,972,842.08 million tons between 2021 and 2030 (14 million tons of lead originated only from motorcycle LABs in 2021). These results show a possible insufficiency of the installed capacity to supply the amount of lead to be processed in the country, not to mention the LABs from other vehicles (light and heavy) and other emerging battery technologies from electric vehicles. In addition, an analysis was conducted on the importance of secondary lead for the economy and the dangers of illegal recycling in Brazil. In general, this study contributes to the understanding of the importance of secondary production of lead in Brazil, an important asset for a country that does not have sufficient primary production for its domestic demand. The findings may assist in several alternatives for the proper planning and management of the collection, disposal and recycling of lead, providing the Brazilian government with directions for the development of new policies related to lead recycling.

Impact of DNA repair polymorphisms on DNA instability biomarkers induced by lead (Pb) in workers exposed to the metal

Although the mechanisms of Pb-induced genotoxicity are well established, a wide individual's variation response is seen in biomarkers related to Pb toxicity, despite similar levels of metal exposure. This may be related to intrinsic variations, such as genetic polymorphisms; moreover, very little is known about the impact of genetic variations related to DNA repair system on DNA instability induced by Pb. In this context, the present study aimed to assess the impact of SNPs in enzymes related to DNA repair system on biomarkers related to acute toxicity and DNA damage induced by Pb exposure, in individuals occupationally exposed to the metal. A cross-sectional study was run with 154 adults (males, >18 years) from an automotive batteries' factory, in Brazil. Blood lead levels (BLL) were determined by ICP-MS; biomarkers related to acute toxicity and DNA instability were monitored by the buccal micronucleus cytome (BMNCyt) assay and genotyping of polymorphisms of MLH1 (rs1799977), OGG1 (rs1052133), PARP1 (rs1136410), XPA (rs1800975), XPC (rs2228000) and XRCC1 (rs25487) were performed by TaqMan assays. BLL ranged from 2.0 to 51 μg dL^-1 (mean 20 ± 12 μg dL^-1) and significant associations between BLL and BMNCyt biomarkers related to cellular proliferation and cytokinetic, cell death and DNA damage were observed. Furthermore, SNPs from the OGG1, XPA and XPC genes were able to modulate interactions in nuclear bud formation (NBUDs) and micronucleus (MNi) events. Taken together, our data provide further evidence that polymorphisms related to DNA repair pathways may modulate Pb-induced DNA damage; studies that investigate the association between injuries to genetic material and susceptibilities in the workplace can provide additional information on the etiology of diseases and the determination of environmentally responsive genes.

Biomonitoring of Exposure to Metals in a Population Residing in an Industrial Area in Brazil: A Feasibility Study

Background: Industries are sources of environmental pollutants. However, there are few human biomonitoring (HBM) studies in the vicinity of industrial areas. Thus, we evaluate the feasibility of conducting an HBM study to assess exposure to metals in an industrial area in Rio de Janeiro, Brazil. Methodology: A cross-sectional survey was conducted near a steel factory. Adults (exposed = 775; controls = 775) were randomly selected and sex-matched. Subjects were interviewed using a questionnaire and a 24 h dietary recall. Blood samples were collected to analyze metal concentrations, blood count, biochemical parameters, and thyroid hormones. The feasibility of the survey was assessed following guidelines. The descriptive analysis was performed for the first 250 participants (pilot study). Results: Adjustments were made to the survey execution, including age-matching, fieldwork team, questionnaire, blood collection, and research awareness. The complete questionnaire was answered by ≥97% of participants; metals were measured in ≥98% and clinical parameters in ≥89%, except thyroid hormones (13–44%). The average age and family income were of 50 years and USD 575/month, respectively. The participants had equal distribution among sexes: 50% had a medium education level, and 59% were nonwhite. Conclusion: This preliminary HBM study demonstrates feasibility for the total population, with results indicating representativeness of the target population.

Development of a benchmark dose for lead-exposure based on its induction of micronuclei, telomere length changes and hematological toxicity

BACKGROUND

Excessive lead exposure is associated with adverse health effects. However, there is a lack of systematic investigation using large populations to ascertain acceptable exposure limits.

OBJECTIVES

Our study was aimed to identify human exposure-response relationships between lead exposure and health-related outcomes, and to determine a benchmark dose (BMD).

METHODS

A total of 1896 participants from a lead-acid battery plant were recruited. Blood lead levels (BLLs) were detected for all participants. Hematological parameters (n = 1896), micronuclei (MN) frequencies (n = 934), and relative telomere length (rTL) (n = 757) were also determined. Multivariate linear/Poisson regression analyses were performed to examine associations between BLLs and these health outcomes. Restricted cubic splines were used to identify dose-response relationships. Three BMD approaches were used to calculate BMD and its 95% lower confidence limit (BMDL).

RESULTS

Among all participants, BLLs show a right-skewed distribution (median, 185.40 μg/L; 25th - 75th percentile, 104.63-271.70 μg/L). There existed significant differences for red blood cell (RBC), hemoglobin (Hb), MN and rTL among different BLL dose groups. After adjusting for possible confounders, all indicators were significantly associated with BLLs. Restricted cubic splines show that there were linear dose-response relationships for RBC and Hb with BLLs, while non-linear for MN and rTL. Results from the three BMD approaches indicate that the dichotomous models were better than continuous models to calculate BMD and BMDL of BLLs. The conservative BMDL obtained from RBC data was 135 for total, 104 for male and 175 μg/L for female. The corresponding BMDL obtained from Hb data was 105 for total, 116 for male and 70 μg/L for female. As for MN data, the BMDL estimate was 66 for total, 69 for male and 64 μg/L for female. Finally, the BMDL from rTL data was 35 for total, 32 for male and 43 μg/L for female.

CONCLUSIONS

Our data show significant dose-response relationships between lead exposure and expressions of hematological toxicity and genotoxicity. The new BMDLs of 135 and 105 μg/L based on RBC and Hb, and even more strict level of 66 and 35 μg/L based on MN and rTL are lower than current exposure limits in China. Therefore, the four values can be considered as novel exposure limits. In addition, sex effect should be taken into account when setting occupational health standard. Considering that different biomarkers have different sensitivities, better understanding their relationships will certainly improve the current emphasis on precision health risk assessment.

Spatial-temporal variability of metal pollution across an industrial district, evidencing the environmental inequality in São Paulo

Although air pollution decreased in some cities that shifted from an industrial to a service-based economy, and vehicular emission regulation became more restrictive, it is still a major risk factor for mortality worldwide. In central São Paulo, Brazil, air quality monitoring stations and tree-ring analyses revealed a decreasing trend in the concentrations of particulate matter and metals. Such trends, however, may not be observed in industrial districts located in the urban periphery, where the usual mobile sources may be combined with local stationary sources. To evaluate environmental pollution in an industrial district in southeastern São Paulo, we assessed its spatial variability, by measuring magnetic properties and concentrations of Al, Ba, Ca, Cl, Cu, Fe, K, Mg, Mn, P, S, Sr, Zn in the bark of 62 trees, and its temporal trends, by measuring Cd, Cu, Ni, Pb, V, Zn in tree rings of three trees. Source apportionment analysis based on tree barks revealed two clusters with high concentrations of metals, one related to vehicular and industrial emissions (Al, Ba, Cu, Fe, Zn) in the east side of the industrial cluster, and the other related to soil resuspension (Cu, Zn, Mn) in its west side. These patterns are also supported by the magnetic properties of bark associated with iron oxides and titanium-iron alloy concentrations. Dendrochemical analyses revealed that only the concentrations of Pb consistently decreased over the last four decades. The concentrations of Cd, Cu, Ni, V, and Zn did not significantly decrease over time, in contrast with their negative trends previously reported in central São Paulo. This combined biomonitoring approach revealed spatial clusters of metal concentration in the vicinity of this industrial cluster and showed that the local population has not benefited from the decreasing polluting metal concentrations in the last decades.

Anti-inflammatory effect of selenium on lead-induced testicular inflammation by inhibiting NLRP3 inflammasome activation in chickens

Lead (Pb) is a deleterious environmental pollutant that is toxic to testes. Selenium (Se) possesses antioxidant and anti-inflammatory properties. Nucleotide-binding domain, leucine-rich-containing family, pyrin-domain containing-3 (NLRP3) inflammasome is involved in inflammatory response. However, the function of NLRP3 inflammasome in antagonistic effect of Se on inflammation caused by Pb remains unknown. The purpose of this research is to identify anti-inflammatory role of Se on testicular toxicity induced by Pb with an emphasis on oxidative stress, inflammation and NLRP3 signaling pathway in chicken. In present study, sixty seven-day-old Hyline male chickens were assigned into four groups. The feeding program consisted of a commercial diet (0.49 mg/kg Se), a Se-supplemented diet (1 mg/kg Se), a Pb-supplemented diet (0.49 mg/kg Se and 350 mg/kg Pb) and a Se-supplemented and Pb-supplemented diet (1 mg/kg Se and 350 mg/kg Pb), respectively. On the 12th week, blood was collected to measure serum testosterone level and testicular tissues were removed to determine Se and Pb concentrations, testicular function, histological structure, oxidative stress indicators and inflammation-related factors (Nuclear factor-kappaB, tumor necrosis factor-α, cyclooxygenase-2, NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain, caspase-1, interluekin (IL)-1β, IL-6, IL-18 and interferon-γ). The experimental results showed that after Pb administration, testicular injury was confirmed via histological assessment; testicular dysfunction were further indicated by decreased testosterone level and mRNA expression of steroidogenic acute regulatory protein, cytochrome P450 side-chain cleavage, 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase. Moreover, NLRP3 signaling pathway activated by Pb-caused oxidative stress was up-regulated accompanied by promotion in reactive oxygen species, nitric oxide, inducible nitric oxide synthase and malondialdehyde and reduction in antioxidants including glutathione peroxidase and glutathione s-transferase. Se administration ameliorated testicular tissue injury, testicular function, oxidative stress and inflammation. In conclusion, Se exhibited antagonistic role in Pb-induced testicular injury via enhancing antioxidant system and inhibiting inflammation in chickens.

Occupational exposure of lead and cadmium on adolescent and adult workers of battery recycling and welding workshops: Adverse impact on health

The occupational exposure of toxic metals is an important concern, because of its potential accumulation in living organisms, leading to long term toxic effects. The occupational and environmental contacts of toxic metals, cadmium (Cd) and lead (Pb) have been evaluated by determination of them in biological samples (blood and scalp hair) of adolescent and adults, workers of battery recycling and welding workshops. The age matched adolescent and adult residing in nonindustrial areas were also selected, termed as referent/control subjects. The blood and scalp hair samples of workers and controls were analyzed for Cd and Pb using graphite furnace atomic absorption spectrometry previously decomposed the matrices using acid mixture. The biochemical parameters of workers of both age groups were also evaluated. The average concentrations of Cd and Pb in blood and scalp hair samples of adolescent workers were three fold higher as compared with control subjects. The drinking water in containers of both workshops contained Pb and Cd in two to four and five to thirteen folds, respectively, higher than recommended permissible limits of WHO. The significant correlations between the blood lead levels and hemoglobin (%) in adolescent (r = -0.78). The positive correlation was observed among incidence of blood pressure with Pb and Cd concentrations in biological samples of workers (adults) (r = 0.65 to 0.83). These findings suggest that occupational exposure of toxic metals might be created adverse impacts on workers due to ill management of workshops.

The association between lead and cadmium co-exposure and renal dysfunction

Both cadmium (Cd) and lead (Pb) exposure can induce kidney damage. However, the effects of combined exposure to Cd and Pb on renal function at environmental levels have not been fully clarified. In this study we investigated the renal function in a Chinese population co-exposed to Cd and Pb. A total of 331 subjects (215 women and 116 men), living in either a control or a polluted area, were included in this study. Cd and Pb in blood and urine (BCd, BPb, UCd, and UPb), and kidney effect markers including urinary N-acetyl-β-D-glucosaminidase (UNAG) and estimated glomerular filtration rate (eGFR), were determined, and the association between exposure markers and renal effect biomarkers were analyzed. The exposure levels in the polluted area were significantly higher than in the control area (all p < 0.01). The eGFR of subjects in the polluted area was decreased compared with that in the control area (p < 0.01). The subjects with high BCd/BPb (BCd ≥ 2 μg/L, BPb ≥ 100 μg/L) or high UCd/UPb (UCd ≥ 3 μg/g creatinine, UPb ≥ 10 μg/g creatinine) showed higher UNAG and UALB levels compared with other subgroups (p < 0.01). The probability of having elevated UNAG in subjects with high BCd/BPb was greater than those with low BCd/BPb [odds ratio (OR) = 2.6, 95% confidence interval (CI): 1.4-4.7), low BCd/high BPb (OR =3.1, 95% CI: 1.4-6.6), and high BCd/low BPb (OR = 1.7, 95% CI: 0.9-3.2). The OR of subjects with low UCd and high UPb, high UCd and low UPb, and high UCd/UPb were 2.9 (95% CI: 1.4-5.7), 3.3 (95% CI: 1.5-7.2), and 7.7 (95% CI: 4.0-14.7), respectively, compared with those with low UCd/UPb. The risk of decrease in eGFR was also higher in subjects with high UCd/UPb than for those with low UCd/UPb (OR = 7.2, 95% CI: 0.8-62.2). Our data demonstrate that Cd and Pb exposure, alone or in combination, are associated with renal impairment. In addition, co-exposure to Pb and Cd propagates the renal tubular dysfunction compared with Cd or Pb exposure alone.

Forecasting model to assess the potential of secondary lead production from lead acid battery scrap

Lead acid battery (LAB) scrap management is an important issue both environmentally and economically. The recovery of lead from battery scrap leads to a reduction in negative impacts of lead mining, as well as making the battery production cycle environmentally friendly. This work aims to propose a forecasting model for lead generation from LAB scrap based on time series modeling that uses data regarding after-market of batteries and new batteries produced for new cars. In order to illustrate the applicability of the new proposal, the model was applied to the Brazilian case. The main results show that at least 1% of LAB scrap from light vehicles have unknown or improper destinations; the efficiency of the recycling process in Brazil is still low, resulting in lead losses close to 4.5%; the lack of a sectorial agreement between the official battery market and the government concerning the reverse logistics of LAB scrap leads to a lack of precise data on the amount of LAB scrap generated and its final destination. Moreover, the economic importance of lead recycling and logistics of the secondary market are also discussed, with a focus on the dangers of illegal recycling.

Tree rings reveal the reduction of Cd, Cu, Ni and Pb pollution in the central region of São Paulo, Brazil

The concern about environmental pollution has risen in the last decades because of its effects on human's health. However, evaluation of the exposure to certain pollutants is currently hampered by the availability of past environmental data. Tree rings are an alternative to reconstruct environmental variability of pre-instrumental periods. Nevertheless, this approach has some reported limitations including migration of chemical elements in the tree rings. The aim of this study was to evaluate the distribution of Cd, Cu, Hg, Na, Ni, Pb, Zn in the tree rings of Tipuana tipu (Fabaceae) to aid the reconstruction of past environmental pollution. We sampled trees in the central region of the city of São Paulo, Brazil, and scanned their tree rings using LA-ICP-MS. We used these data to evaluate the temporal trends of chemical elements under investigation. Results show a non-random distribution of these chemical elements within the tree rings, with higher content in the cell-walls of vessels and lower content in the fibers. Sodium was the only element intimately related to the axial parenchyma cells. Due to differences in elemental composition of xylem cells, temporal trends where evaluated using distinct quartiles of data distribution in each tree ring. The first quartile represents the lower content found in fibers and parenchyma, while the third quartile corresponds to the higher content found in vessels. Data from vessels better represent the decreasing trend of Cd, Cu, Pb, and Ni in the last three decades. This reduction is less significant for Na and Zn. Our results highlight the potential to improve the records of environmental pollution using data from different cells. Pronounced reduction in Pb may be attributed to the lead phase-out in gasoline, while the decreasing trend of Cd, Cu, Ni pollution is probably related to increasing efficiency of vehicles and the deindustrialization of São Paulo. Chemical elements are non-randomly distributed in tree rings. Chemical content of vessels cell-walls is a reliable record of metal pollution, which is decreasing in São Paulo.

Lead induces DNA damage and alteration of ALAD and antioxidant genes mRNA expression in construction site workers

Oxidative stress and DNA damage are considered as possible mechanisms involved in lead toxicity. To test this hypothesis, DNA damage and expression variations of aminolevulinic acid dehydratase (ALAD), superoxide dismutase 2 (SOD2), and 8-oxoguanine DNA glycosylase 2a (OGG1-2a) genes was studied in a cohort of 100 exposed workers and 100 controls with comet assay and real-time polymerse chain reaction (PCR). Results indicated that increased number of comets was observed in exposed workers versus controls (p < 0.001). After qPCR analysis, significant down-regulation in ALAD (p < 0.0001), SOD2 (p < 0.0001), and OGG1-2a (p < 0.0001) level was observed in exposed workers versus controls. Additionally, a positive spearmen correlation was observed between ALAD versus SOD2 (r = 0.402**, p < 0.001), ALAD versus OGG1-2a (r = 0.235*, p < 0.05), and SOD2 versus OGG1-2a (r = 0.292*, p < 0.05). This study showed that lead exposure induces DNA damage, which is accompanied by an elevated intensity of oxidative stress and expression variation of lead-related gene.

Milk and Dairy Products Intake Is Associated with Low Levels of Lead (Pb) in Workers highly Exposed to the Metal

Lead (Pb) is a toxic metal, frequently associated with occupational exposure, due to its widespread use in industry and several studies have shown high Pb levels in workers occupationally exposed to the metal. The aim of this study was to evaluate the influence of milk and dairy products (MDP) on Pb levels in blood (B-Pb), plasma (P-Pb), and urine (U-Pb), in workers from automotive battery industries in Brazil. The study included 237 male workers; information concerning diet and lifestyle were gathered through a questionnaire, and B-Pb, P-Pb, and U-Pb were determined by ICP-MS. Mean B-Pb, P-Pb, and U-Pb were 21 ± 12, 0.62 ± 0.73 μg/dL, and 39 ± 47 μg/g creatinine, respectively. Forty three percent of participants declared consuming ≤3 portions/week of MDP (classified as low-MDP intake), while 57% of individuals had >3portions/week of MDP (high-MDP intake). B-Pb and P-Pb were correlated with working time (r _s  = 0.21; r _s  = 0.20; p < 0.010). Multivariable linear regressions showed a significant influence of MDP intake on B-Pb (β = -0.10; p = 0.012) and P-Pb (β = -0.16; p < 0.010), while no significance was seen on U-Pb. Our results suggest that MDP consumption may modulate Pb levels in individuals highly exposed to the metal; these findings may be due to the Pb-Ca interactions, since the adverse effects of Pb are partially based on its interference with Ca metabolism and proper Ca supplementation may help to reduce the adverse health effects induced by Pb exposure.

Assessment of exposure to cadmium, lead, manganese, and nickel in workers from foundries

Objectives:

In this study, biological exposure indicators were used to assess the exposure of workers to cadmium (Cd), lead (Pb), manganese (Mn), and nickel (Ni) in nonferrous metal smelters.

Methods:

A total of 273 male participants (178 exposed and 95 nonexposed control group), working in nonferrous metal foundries located in southern Brazil, were evaluated based on biological indicators, environmental levels, and different types of work performed by the participants. Blood Pb (BPb), urinary Cd (UCd), urinary Mn (UMn), and urinary Ni (UNi) levels were quantified by graphite furnace atomic absorption spectrometry with Zeeman background correction.

Results:

Significant differences between the exposed and nonexposed groups were observed for all of the analyzed elements. The average levels of BPb were higher than the recommended occupational exposure level. Relatively low concentrations were found for UCd, UMn, and UNi.

Conclusions:

Although metal production is an important segment of the Brazilian economy, information related to employee health in this sector is scarce. The environmental levels are determinant in occupational exposure in foundries. In companies where air levels of Pb, Cd, and Mn were above the established limits, the different types of activity did not represent an important influence on the biological levels found among workers. In situations with low air levels of these metals, the workers from the “melting” sector were actually more vulnerable.

Lead concentration in the blood of the general population living near a lead-zinc mine site, Nigeria: Exposure pathways

Lead (Pb) poisoning in children is a major public health catastrophe worldwide. This report summarises both exposure pathways and blood Pb levels in children below 7 years of age and adults (above 18 years) from the Adudu community living near a lead-zinc mine in Nasawara, Nigeria. The average and median blood Pb levels in children and adults were 2.1 and 1.3 μg/dL, 3.1 and 1.8 μg/dL, respectively. However, Pb in 14% of adults' blood exceeded 5 μg/dL, which is the recommended threshold blood Pb concentration in adults as established by the Centers for Disease Control and Prevention (CDC). Furthermore 68% of adults' blood exceeded blood Pb action level of 2 μg/dL. For children, 11.4% and 31% of the blood samples exceeded 5 μg/dL and 2 μg/dL, respectively, while no safe blood Pb level in children has been recommended. In Nasawara, a significant difference (p<0.05) was observed between the various age groups in children with 2-4 years old having the highest levels and 6 year old children having the lowest Pb levels. Although this study did not detect elevated levels of Pb in children's blood in regions such as Zamfara, Nigeria and Kabwe, Zambia, a high percentage of samples exceeded 2 μg/dL. Soils, floor dusts, water and crops also reveal that Pb contamination in the study area could potentially be the major cause of blood Pb in the community exposed to mining. This study also observed a significant correlation between water Pb levels of adults and blood Pb levels, suggesting that water is the major exposure pathway. This analysis highlights the need to properly manage mining activities so that the health of communities living in the vicinity of a Pb-Zn mine is not compromised.

Effects of Lead Exposure and Genetic Polymorphisms on ALAD and GPx Activities in Brazilian Battery Workers

Lead (Pb) is a toxic metal that is widely used by metallurgical industries such as car battery recycling. Exposure to the metal may modify the redox status of the cells and consequently result in changes in activities of important enzymes such as delta-aminolevulinic acid dehydratase (ALAD) and glutathione peroxidase (GPx). Similarly, genetic polymorphisms may modulate the activities of enzymes related to detoxification processes of the metal and may modify Pb body burden. Therefore, the aims of the present study were (i) to evaluate the correlation between blood lead levels (BLL) and activities of the enzymes ALAD and GPx, and (ii) to determine whether activities of these enzymes may be influenced by polymorphisms in ALAD and GPx genes in Brazilian automotive battery workers chronically exposed to Pb, as well as the effects of these polymorphisms on BLL. Our study included 257 participants; BLL were determined by inductively couple plasma-mass spectrometry (ICP-MS), and the activities of the enzymes ALAD and GPx were quantified spectrophotometrically; and genotyping of ALAD (rs1800435) and GPx-1 (rs1800668) polymorphisms was performed by TaqMan assays (real-time polymerase chain reaction, RT-PCR). Significant negative correlations were found between BLL and ALAD activity. Subjects who carried at least one polymorphic allele for ALAD gene displayed markedly lower ALAD activities, while no significant effect was observed regarding GPx-1 polymorphism and activity of the same enzyme. Further, ALAD and GPx-1 polymorphisms exerted no marked influence on BLL. Taken together, our results showed that BLL affected ALAD but not GPx activities, and these were not modulated by polymorphisms in ALAD and GPx gene. Further, the rs1800435 SNP showed a tendency to modulate ALAD activity, while the rs1800668 SNP did not modulate GPx activity in Brazilian automotive battery workers exposed to Pb.

Levels and source apportionment of children's lead exposure: could urinary lead be used to identify the levels and sources of children's lead pollution?

As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as (207)Pb/(206)Pb, (208)Pb/(206)Pb and (204)Pb/(206)Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis.

Risk factors for lead exposure in adult population in southern Brazil

In Brazil there is no systematic evaluation to access blood lead levels (BLL) in the general population and few studies with adults have been published. The aim of this study was to examine the socioeconomic, environmental, and lifestyle determinants of BLL in the adult Brazilian population. In total, 959 adults, aged 40 years or more, were randomly selected in a city in southern Brazil. Information on socioeconomic, dietary, lifestyle, and occupational background was obtained by interviews. A spatial analysis was conducted to discern whether there were any identifiable sources of exposure. BLL were measured by inductively coupled plasma-mass spectrometry. There was an adjustment for gender, age, race, education, income class, smoking status, alcohol consumption, occupation, and red meat or cow milk consumption (Model 1), and for occupation and gender (Model 2). The geometric mean of BLL was 1.97 μg/dl (95% CI: 1.9-2.04 μg/dl). In Model 1, BLL were positively associated with male gender, older age, and drinking and smoking habits, and less frequently with milk consumption. In Model 2, data showed higher BLL in non-white than white participants, in former smokers and individuals with current or former employment in lead (Pb) industries. The participants living in the area with more Pb industries had higher BLL (3.3 μg/dl) compared with those residing in other areas with no or fewer Pb industries (1.95 μg/dl). Despite the low BLL found in adults living in an urban area, Pb industries need to be monitored and regulatory laws implemented to prevent metal contamination in urban settings.

Are delta-aminolevulinate dehydratase inhibition and metal concentrations additional factors for the age-related cognitive decline?

Aging is often accompanied by cognitive impairments and influenced by oxidative status and chemical imbalances. Thus, this study was conducted to examine whether age-related cognitive deficit is associated with oxidative damage, especially with inhibition of the enzyme delta-aminolevulinate dehydratase (ALA-D), as well as to verify the influence of some metals in the enzyme activity and cognitive performance. Blood ALA-D activity, essential (Fe, Zn, Cu, Se) and non-essential metals (Pb, Cd, Hg, As, Cr, Ni, V) were measured in 50 elderly and 20 healthy young subjects. Cognitive function was assessed by tests from Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) battery and other. The elderly group presented decreased ALA-D activity compared to the young group. The index of ALA-D reactivation was similar to both study groups, but negatively associated with metals. The mean levels of essential metals were within the reference values, while the most toxic metals were above them in both groups. Cognitive function impairments were observed in elderly group and were associated with decreased ALA-D activity, with lower levels of Se and higher levels of toxic metals (Hg and V). Results suggest that the reduced ALA-D activity in elderly can be an additional factor involved in cognitive decline, since its inhibition throughout life could lead to accumulation of the neurotoxic compound ALA. Toxic metals were found to contribute to cognitive decline and also to influence ALA-D reactivation.

Reference values of lead in blood and related factors among blood donors in the Western Amazon, Brazil

The aim of this study was to (1) determine the reference value of blood lead levels (BLL) in a sample of blood donors of Rio Branco, the capital city of Acre, in the Western Brazilian Amazon, and (2) explore factors influencing lead (Pb) exposure levels. Between 2010 and 2011, blood samples were collected from universal blood donors attending the Central Hemotherapic Unit in Rio Branco with a total number of 1196. Information on characteristics of 1183 donors was obtained through questionnaires. Blood Pb concentrations were determined by inductively coupled plasma-mass spectrometry with detection limit of 0.003 μg/L. Association between BLL and participant characteristics was examined by linear regression analysis. Reference values of BLL were calculated as the upper limit of the 95% confidence interval of the 95th percentile. Reference values of BLL were 109.5 μg/L for men, 70.7 μg/L for women, 88.9 μg/L for younger individuals (18-29 yr), 115.3 μg/L for older ones (≥30 yr), 94.2 μg/L for nonsmokers, and 164.5 μg/L for smokers. Levels of BLL were significantly higher in males, subjects older than 29 yr, non-whites, smokers, regular consumers of manioc flour, and donors practicing any activity related to paints, ceramics, pottery, fishing, or firearms. Subjects with higher education, higher income, vitamin intake use, and drinkers of bottled water displayed lower BLL. In general, BLL in men and women from Rio Branco were higher than those described in other adult populations. Prevention of exposure of this population to local sources of Pb needs to be addressed.

Human biological monitoring of suspected endocrine-disrupting compounds

Endocrine-disrupting compounds are exogenous agents that interfere with the natural hormones of the body. Human biological monitoring is a powerful method for monitoring exposure to endocrine disrupting compounds. In this review, we describe human biological monitoring systems for different groups of endocrine disrupting compounds, polychlorinated biphenyls, brominated flame retardants, phthalates, alkylphenols, pesticides, metals, perfluronated compounds, parabens, ultraviolet filters, and organic solvents. The aspects discussed are origin to exposure, metabolism, matrices to analyse, analytical determination methods, determinants, and time trends.

Manioc flour consumption as a risk factor for lead poisoning in the Brazilian Amazon

Recent studies reported elevated blood lead (Pb) levels in riparian populations of the Amazon. For this reason, the aim of the present study was to assess the risk to riparians in the Brazilian Amazon to Pb exposure due to the intake of contaminated manioc flour. Lead levels were determined in whole blood (n = 74) and in manioc flour samples (n = 30) in three different communities. Mean blood Pb levels were 16.8 μg/dl, with individuals living in Açaituba presenting the highest mean blood Pb level (22.4 μg/dl), followed by Nova Canaã (17.3 μg/dl) and Santa Cruz (9.8 μg/dl). The minimum blood Pb level found was 0.83 μg/dl and the maximum was 44.3 μg/dl. The estimated daily intake (EDI) was calculated and compared to the benchmark dose lower confidence limit (BMDL) for neurotoxicity. Mean Pb in manioc flour was 0.34 μg/g while EDI was 79 μg/d, corresponding to 260% of the BMDL (varying from 168 to 308%). This finding is of great importance since this high EDI may exert adverse effects on the nervous system of this population. Manioc flour intake may thus present considerable risk of Pb exposure in this region. Risk management strategies and further studies on adverse effects in this population are needed.

Environmental lead poisoning among children in Porto Alegre state, Southern Brazil

OBJECTIVE

To estimate the prevalence of lead poisoning in children and to identify associated factors, as well as possible local sources of contamination.

METHODS

A cross-sectional prevalence study conducted in 2006 with a random sample of 97 children age zero to five years from a neighborhood in Porto Alegre, Southern Brazil. Blood lead levels were measured and a questionnaire administered to collect information on sociodemographics, recycling and dwelling. A preliminary environmental evaluation was carried out with direct analysis of soil and indirect analysis of air pollution with bioindicators to identify possible sources of contamination. To analyze lead concentrations from the different collection sites, for each type of material studied, ANOVA was performed with a Brown-Forsythe adjustment for heteroscedasticity and with Dunnett's T3 procedure for multiple comparisons of unequal variances.

RESULTS

Blood lead levels > 10.0 µg/dL was found in 16.5% of children. Recycling of waste at home, low father's education level, and increased age of children were associated with increase blood lead levels. High lead levels were found in soil, and there was little indication of lead air pollution.

CONCLUSIONS

A high prevalence of lead poisoning was identified, and the potential sources of contamination in this community appear related to waste recylcing activities. Studies should be conducted with other populations of Brazilian children and evaluate potential sources of local and general contamination, to accurately characterize this issue in Brazil.

Occupational exposure profile of Pb, Mn, and Cd in nonferrous Brazilian sanitary alloy foundries

In addition to the primary components of alloys, approximately 5% of the formulation may contain other metals, including lead (Pb), cadmium (Cd), arsenic, manganese (Mn), iron, phosphorus, and nickel. Workers in the foundries are exposed to several compounds; therefore, it is important to assess the levels of injury that may reflect an additive, synergistic, or antagonistic effect caused by these compounds. The mean values of the environmental evaluation of the facilities range from 16.65 to 40.31 µg m−3 for Pb, 0.99 to 1.73 µg m−3 for Cd, and 0.91 to 1.70 µg m−3 for Mn. The mean values of the metal concentrations for furnace, mold, melting, and automatic melting activities range from 15.37 to 19.26 µg m−3 for Pb, 7.07 to 9.14 µg m−3 for Cd, and 8.83 to 16.00 µg m−3 for Mn. Biological samples were divided into two groups: control ( n = 38) and exposed ( n = 45). The obtained data are3.41 ± 3.40 and 14.89 ± 7.82 µg dL−1 for Pb, 0.90 ± 0.80 and 1.91 ± 1.90 µg g−1 creatinine for Cd, and 0.51 ± 0.40 and 3.17 ± 1.93 µg g−1 creatinine for Mn. Statistical analysis showed significant differences ( p < 0.05). Positive linear correlations were established between metal concentrations in the air and the biological matrixes: Pb ( r = 0.68; p < 0.001), Cd ( r = 0.81; p = 0.17), and Mn ( r = 0.12; p < 0.03). Regression analysis showed that professional activities can interfere with element exposure profiles in occupational settings. The analysis in the event of exposure to metals in these companies allowed investigating whether the simultaneous exposure leads to biological damage even if the levels of the compounds are within the exposure limits that are considered to be safe.

A systematic review on status of lead pollution and toxicity in Iran; Guidance for preventive measures

Lead is an old environmental metal which is presented everywhere and lead poisoning is an important health issue in many countries in the world including Iran. It is known as a silent environmental disease which can have life-long adverse health effects. In children, the most vulnerable population, mental development of children health effects is of the greatest influence. Low level lead exposure can significantly induce motor dysfunctions and cognitive impairment in children. The sources of lead exposure vary among countries. Occupational lead exposure is an important health issue in Iran and mine workers, employees of paint factories, workers of copying centers, drivers, and tile making factories are in higher risk of lead toxicity. Moreover lead processing industry has always been a major of concern which affects surface water, drinking waters, and ground waters, even water of Caspian Sea, Persian Gulf and rivers due to increasing the number of industries in vicinity of rivers that release their waste discharges into river or sea. In addition, lead contamination of soil and air especially in vicinity of polluted and industrialized cities is another health problem in Iran. Even foods such as rice and fishes, raw milk, and vegetables which are the most common food of Iranian population are polluted to lead in some area of Iran. Adding lead to the opium is a recently health hazard in Iran that has been observed among opium addicts. There are few studies evaluated current status of lead exposure and toxicity in the Iranian children and pregnant women which should be taken into account of authorities. We recommend to identify sources, eliminate or control sources, and monitor environmental exposures and hazards to prevent lead poisoning.

Reference values for lead, cadmium and mercury in the blood of adults from the metropolitan area of Sao Paulo, Brazil

Human biomonitoring is an important tool for the evaluation of environmental exposure to contaminants. The data that are obtained from these studies might be compared to appropriate reference values (RVs) in a specific population. The RVs were derived from the rounded values of the upper limit of the 95th confidence interval of the 95th percentile for lead (Pb), cadmium (Cd) and mercury (Hg) in blood from adults in the metropolitan area of Sao Paulo (MASP), Brazil to investigate the association between blood metals and sociodemographic and lifestyle factors. Blood samples from 653 nonsmoking blood donors without occupational exposure to the studied metals were collected in 2006. Our evaluations distinguished a younger group (18-39 years) and an older group (40-65 years). RVs in the younger group were 60 μgPb/L and 4 μgHg/L for men and 47 μgPb/L and 4 μgHg/L for women. RVs in the older group were 80 μgPb/L and 5 μgHg/L for men and 63 μgPb/L and 6 μgHg/L for women. The RV for Cd was 0.6 μg/L for adults aged 18-65 years. Pb and Cd levels demonstrated a significant association with sex and age. Male blood contained 50% more Pb, and the older group exhibited 23% more Pb. Fish consumption and amalgam fillings were primarily related to Hg levels. RVs for lead were similar to the Czech Republic and Germany but higher than the US population. The RV for Cd in Brazil was well below the RVs of these countries. The RVs for Hg in Brazil were similar to the US but higher than Germany and the Czech Republic.

Air and blood lead levels in lead acid battery recycling and manufacturing plants in Kenya

The concentration of airborne and blood lead (Pb) was assessed in a Pb acid battery recycling plant and in a Pb acid battery manufacturing plant in Kenya. In the recycling plant, full-shift area samples taken across 5 days in several production sections showed a mean value ± standard deviation (SD) of 427 ± 124 μg/m(3), while area samples in the office area had a mean ± SD of 59.2 ± 22.7 μg/m(3). In the battery manufacturing plant, full-shift area samples taken across 5 days in several production areas showed a mean value ± SD of 349 ± 107 μg/m(3), while area samples in the office area had a mean ± SD of 55.2 ± 33.2 μg/m(3). All these mean values exceed the U.S. Occupational Safety and Health Administration's permissible exposure limit of 50 μg/m(3) as an 8-hr time-weighted average. In the battery recycling plant, production workers had a mean blood Pb level ± SD of 62.2 ± 12.7 μg/dL, and office workers had a mean blood Pb level ± SD of 43.4 ± 6.6 μg/dL. In the battery manufacturing plant, production workers had a mean blood Pb level ± SD of 59.5 ± 10.1 μg/dL, and office workers had a mean blood Pb level ± SD of 41.6 ± 7.4 μg/dL. All the measured blood Pb levels exceeded 30 μg/dL, which is the maximum blood Pb level recommended by the ACGIH(®). Observations made in these facilities revealed numerous sources of Pb exposure due to inadequacies in engineering controls, work practices, respirator use, and personal hygiene.

Whole blood, serum, and saliva lead concentrations in 6- to 8-year-old children

With increasing evidence of adverse health effects of lower lead levels (below 10microg/dL in whole blood), studies on novel internal dose biomarkers are needed. This study aimed at: (1) assessing the lead exposure by measuring this element in whole blood (Pb-blood), serum (Pb-serum), and 3 different types of saliva: whole (Pb-whole-saliva), submandibular/sublingual (Pb-sub-saliva) and parotid saliva (Pb-parotid-saliva); (2) correlating Pb-blood with Pb-serum; and (3) relating Pb-blood and Pb-serum with the lead found in the different salivas. The study population included 444 children aged 6 to 8 years attending 4 government schools in the district of Campos Eliseos, in Ribeirao Preto, Sao Paulo State, Brazil. Whole blood, serum, parotid, submandibular/sublingual ("sub-saliva"), and whole saliva were collected in trace element-free tubes. Lead concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Median Pb-blood and Pb-serum were 2.1microg/dL and 0.4microg/L, respectively. Ten percent of the children had Pb-blood between 4.0 and 9.4microg/dL. Boys showed higher Pb-blood than girls (2.3 vs. 2.0microg/dL, p<0.0003). Lead concentrations in whole, sub, and parotid saliva were 1.7, 1.4, and 1.3microg/L, respectively. No significant correlations were found between Pb-blood and Pb-serum, between Pb-blood and lead in the 3 different salivas, or between Pb-serum and Pb-whole-saliva or Pb-sub-saliva. However, there was a weak statistically significant correlation between Pb-serum and Pb-parotid-saliva. In conclusion, the mean Pb-blood concentration was 2.4microg/dL, with 10% of the children exhibiting Pb-blood between 4.0 and 9.4microg/dL. Boys presented higher Pb-blood. Results suggest that Pb-blood has no correlation with Pb-serum or lead in the 3 different salivas collected here. A weak but statistically significant correlation between Pb-serum and Pb-parotid-saliva was found. Our results also point to the need for carrying out more studies on sources of exposure and lead levels in children in Brazil.

Avaliação dos fatores de risco relacionados à exposição ao chumbo em crianças e adolescentes do Rio de Janeiro

A importância do chumbo atmosférico na contaminação global do ambiente tem recebido crescente atenção científica. A principal forma de monitorização da exposição é biológica, mas a ambiental tem um papel importante, já que o ambiente é a principal fonte de exposição ao chumbo. O estudo transversal busca identificar fontes de contaminação e potenciais fatores de risco da exposição em 64 crianças de zero a dezesseis anos de uma comunidade economicamente desfavorecida do Rio de Janeiro. Foram determinadas as concentrações de chumbo em solo, água, poeira e ar e calculados os fatores de risco neurológico e carcinogênico de inalação e ingestão. O sangue coletado foi utilizado para análise de Pb-S, ALA-D% e genotipagem da ALA-D. O fator de risco neurológico observado foi 549 vezes superior à dose de referência para poeira e 554 vezes superior no caso de ingestão. O fator de risco carcinogênico para ingestão foi de quatro vezes. A média de Pb-S foi 5,6μg/dL e 40% das crianças apresentaram valores de Pb-S acima do ponto de corte de 6μg/dL. A média de ALA-D% foi 40,3% e foi observada correlação entre Pb-S e ALA-D%. O genótipo ALAD1-2 foi identificado em 10% das crianças. Os resultados deste estudo permitirão o conhecimento da nossa realidade, subsidiando os órgãos de saúde pública e meio ambiente nas ações de controle e vigilância ambiental integrada

Evaluation of calcium excretion in Brazilian infantile and young population environmentally exposed to lead

Lead exposure is an important issue in the research of several toxic effects resulting from the biochemical interaction between this metal and the organism. Calcium is a fundamental mineral for the maintenance of the organism homeostasis where there is interaction between lead and calcium in metabolic pathways. Environmental lead exposure by verifying the usefulness and applicability of urinary calcium/creatinine ratio (UCa/Cr) in this context was evaluated. This was an extensive socio-demographic study of the nutritional profile, lead exposure biomarkers in blood and the urine and UCa/Cr ratio. The children studied were from a low socio-economic group characterized by unsatisfactory nutritional diet. Lead environmental exposure was shown by biomarkers, with UCa/Cr ratio having positive and significant correlations with both lead and delta-aminolevulinic acid in urine (ALA-U), without colinearity diagnosis. There was a strong association between calcium excretion and lead exposure as a result of linear regression construction models. In children, lead increases calcium excretion which is an additional risk to infantile health. Urinary calcium/creatinine ratio may be a useful tool in the biological monitoring of lead exposure and health promotion programs.

Elevated blood lead levels in a riverside population in the Brazilian Amazon

Lead (Pb) is recognized as one of the most toxic metals. Sources of Pb exposure have been widely documented in North America, and the removal of Pb additives from gasoline was reflected in a dramatic lowering of blood Pb concentration. In Latin America, the removal of Pb from gasoline resulted in decreased exposure, but Pb levels in many areas remain high due to occupational and environmental sources of exposure. While many of the Pb sources have been identified (mining, industries, battery recycling, lead-based paint, ceramics), new ones occasionally crop up. Here we report on blood Pb (B-Pb) levels in remote riverside communities of the Brazilian Amazon. Blood Pb (B-Pb) levels were determined in 448 persons from 12 villages of the Lower Tapajós River Basin, Pará, Brazil. Socio-demographic and dietary information, as well as occupational, residential and medical history was collected using an interview-administered questionnaire. B-Pb, measured by ICP-MS, showed elevated concentrations. Mean B-Pb was 13.1 microg/dL +/- 8.5, median B-Pb was 11.2 microg/dL and ranged from 0.59 to 48.3 microg/dL. Men had higher B-Pb compared to women (median: 15.3 microg/dL vs 7.9 microg/dL respectively). B-Pb increased with age for women, while it decreased for men. For both genders, B-Pb decreased with education. There were significant differences between villages. Exploratory analyses, using linear partition models, showed that for men B-Pb was lower among those who were involved in cattle-raising, and higher among those who hunted, farmed and fished. The distribution profile of B-Pb directed us towards artisanal transformation of manioc to flour (farinha), which requires heating in a large metal pan, with stirring primarily done by young men. In the village with the highest B-Pb, analysis of Pb concentrations (dry weight) of manioc (prior to transformation) and farinha (following transformation) from 6 houses showed a tenfold increase in Pb concentration (mean: 0.017 +/- 0.016 to 0.19 +/- 0.10 microg/g). This was confirmed in one of these villages where we sampled manioc paste (just before roasting) and the roasted farinha (0.05 microg/g vs 0.20 microg/g). While there may be other sources (ammunition, sinkers for fishing nets), the high concentrations in farinha, a dietary staple, assuredly makes an important contribution. Further action needs to reduce Pb sources in this region.

Relationships of blood lead to calcium, iron, and vitamin C intakes in Brazilian pregnant women

BACKGROUND & AIMS

This study aimed to determine the relationship between blood lead concentrations and calcium, iron and vitamin C dietary intakes of pregnant women.

METHODS

Included in the study were 55 women admitted to a hospital, for delivery, from June to August 2002. A food frequency questionnaire was applied to determine calcium, iron and vitamin C intakes, and a general questionnaire to obtain data on demographic-socioeconomic condition, obstetric history, smoking habit, and alcohol intake. Blood lead and haemoglobin were determined, respectively, by atomic absorption spectrometry and by the haemoglobinometer HemoCue. Multiple linear regression models were used to determine the relationship between blood lead and calcium, iron and vitamin C intakes, and haemoglobin levels, controlling for confounders.

RESULTS

The final model of the regression analysis detected an inverse relationship between blood lead and age of the women (p=0.011), haemoglobin (p=0.001), vitamin C (p=0.012), and calcium intake (p<0.001) (R(2)=0.952). One hundred percent, 98.2% and 43.6% of the women were below the adequate intake (AI) for calcium, and below the recommended dietary allowances (RDA) for iron, and vitamin C, respectively.

CONCLUSION

Despite the small sample size, the results of this study suggest that maternal age, haemoglobin, vitamin C intake, and calcium intake may interfere with blood concentrations of lead.

Lead contents in the surface enamel of deciduous teeth sampled in vivo from children in uncontaminated and in lead-contaminated areas

This study aimed to: (1) measure lead contents in the surface enamel of two populations consisting of 4-6-year-old children, one from an apparently uncontaminated area (Ribeirão Preto, São Paulo State, SP, Brazil, n=247) and the other from an area notoriously contaminated with lead (Bauru, São Paulo State, Brazil, n=26); (2) compare biopsy depths between the two populations; (3) correlate biopsy depth with lead content; (4) stratify samples according to biopsy depth to compare lead contents in samples from similar biopsy depths. A surface enamel acid-etch microbiopsy was performed in vivo on a single upper deciduous incisor for each sample. Lead was measured by graphite furnace atomic absorption spectrometry (GFAAS) while phosphorus was measured colorimetrically to establish biopsy depth. Samples from both populations were classified into categories of similar biopsy depths based on biopsy depth quartiles. Median lead contents were statistically different between the Ribeirão Preto population (206 microg/g, range: 5-1399 microg/g) and the Bauru population (786 microg/g, range: 320-4711 microg/g) (p<0.001); however, biopsy depth did not differ between the Ribeirão Preto (3.9 microm, Standard Deviation, SD=0.9) and Bauru (3.8 microm, SD=0.9) populations (p=0.7940). Pearson's correlation coefficient for biopsy depths versus log10 lead values was -0.29 for Ribeirão Preto and -0.18 for Bauru. Lead contents were statistically different between the two populations for all quartiles of biopsy depth. These findings suggest that lead accumulated in the surface enamel of deciduous teeth is linked to the environment in which people reside, indicating that this tissue should be further explored as an accessible biomarker of lead exposure.