Evaluation of genotoxic effects of lead in pottery-glaze workers using micronucleus assay, alkaline comet assay and DNA diffusion assay

The Comet Assay as a Tool in Human Biomonitoring Studies of Environmental and Occupational Exposure to Chemicals-A Systematic Scoping Review

Biomonitoring of human populations exposed to chemical substances that can act as potential mutagens or carcinogens, may enable the detection of damage and early disease prevention. In recent years, the comet assay has become an important tool for assessing DNA damage, both in environmental and occupational exposure contexts. To evidence the role of the comet assay in human biomonitoring, we have analysed original research studies of environmental or occupational exposure that used the comet assay in their assessments, following the PRISMA-ScR method (preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews). Groups of chemicals were designated according to a broad classification, and the results obtained from over 300 original studies (n = 123 on air pollutants, n = 14 on anaesthetics, n = 18 on antineoplastic drugs, n = 57 on heavy metals, n = 59 on pesticides, and n = 49 on solvents) showed overall higher values of DNA strand breaks in the exposed subjects in comparison with the unexposed. In summary, our systematic scoping review strengthens the relevance of the use of the comet assay in assessing DNA damage in human biomonitoring studies.

Exploring cytokinesis block micronucleus assay in Croatia: A journey through the past, present, and future in biomonitoring of the general population

In this study, we used the cytokinesis-block micronucleus (CBMN) assay to evaluate the background frequency of cytogenetic damage in peripheral blood lymphocytes of the general population concerning different anthropometric data and lifestyle factors. The background frequency of CBMN assay parameters was analysed in 850 healthy, occupationally non-exposed male and female subjects (average age, 38±11 years) gathered from the general Croatian population from 2000 to 2023. The mean background values for micronuclei (MNi) in the whole population were 5.3±4.3 per 1000 binucleated cells, while the mean frequency of nucleoplasmic bridges (NPBs) was 0.7±1.3 and of nuclear buds (NBUDs) 3.1±3.2. The cut-off value, which corresponds to the 95th percentile of the distribution of 850 individual values, was 14 MNi, 3 NPBs, and 9 NBUDs. Results from our database also showed an association of the tested genomic instability parameters with age and sex but also with other lifestyle factors. These findings underscore the importance of considering several anthropometric and lifestyle factors when conducting biomonitoring studies. Overall, the normal and cut-off values attained here present normal values for the general population that can later serve as baseline values for further human biomonitoring studies either in Croatia or worldwide.

Occupational Lead Exposure Ototoxicity Evaluated With Distortion-Product Otoacoustic Emissions

OBJECTIVES

To evaluate the extent of hearing loss among pottery workers in Mexico exposed to lead.

DESIGN

The authors conducted a cross-sectional study including 315 adult pottery workers. Auditory function was evaluated by air conduction pure-tone audiometry (pure-tone average) and distortion-product otoacoustic emission (DPOAE) levels (amplitude and signal-to-noise ratio). Lead exposure was assessed with a single blood sample test and classified as low, medium, and high according to blood lead tertiles. Logistic regression models were calculated for the association between blood lead levels, pure-tone average, and DPOAE records.

RESULTS

Median (25th-75th) blood lead levels were 14 μg/dL (7.5-22.6 μg/dL). The audiometric pattern and DPOAE records were similar across blood lead levels groups in all frequencies, and no statistically significant differences were found. Adjusted logistic regression models showed no increase in the odds for hearing thresholds >25 dB (HL) and DPOAE absence associated with blood lead levels, and no dose-response pattern was observed ( p > 0.05).

CONCLUSIONS

Given the results from this cross-sectional study, no association was found between blood lead levels and hearing loss assessed with DPOAE. Future longitudinal work should consider chronic lead exposure estimates among underrepresented populations, which can potentially inform safer work practices to minimize the risk of ototoxicity.

Cadmium exposure and DNA damage (genotoxicity): a systematic review and meta-analysis

Existing literature suggests an association between chronic cadmium (Cd) exposure and the induction of DNA damage and genotoxicity. However, observations from individual studies are inconsistent and conflicting. Therefore current systematic review aimed to pool evidence from existing literature to synthesize quantitative and qualitative corroboration on the association between markers of genotoxicity and occupational Cd exposed population. Studies that evaluated markers of DNA damage among occupationally Cd-exposed and unexposed workers were selected after a systematic literature search. The DNA damage markers included were chromosomal aberrations (chromosomal, chromatid, sister chromatid exchange), Micronucleus (MN) frequency in mono and binucleated cells (MN with condensed chromatin, lobed nucleus, nuclear buds, mitotic index, nucleoplasmatic bridges, pyknosis, and karyorrhexis), comet assay (tail intensity, tail length, tail moment, and olive tail moment), and oxidative DNA damage (8-hydroxy-deoxyguanosine). Mean differences or standardized mean differences were pooled using a random-effects model. The Cochran-Q test and I² statistic were used to monitor heterogeneity among included studies. Twenty-nine studies with 3080 occupationally Cd-exposed and 1807 unexposed workers were included in the review. Cd among the exposed group was higher in blood [4.77 μg/L (-4.94-14.48)] and urine samples [standardized mean difference 0.47 (0.10-0.85)] than in the exposed group. The Cd exposure is positively associated with higher levels of DNA damage characterized by increased frequency of MN [7.35 (-0.32-15.02)], sister chromatid exchange [20.30 (4.34-36.26)], chromosomal aberrations, and oxidative DNA damage (comet assay and 8OHdG [0.41 (0.20-0.63)]) compared to the unexposed. However, with considerable between-study heterogeneity. Chronic Cd exposure is associated with augmented DNA damage. However, more extensive longitudinal studies with adequate sample sizes are necessary to assist the current observations and promote comprehension of the Cd's role in inducing DNA damage.Prospero Registration ID: CRD42022348874.

Association between lead exposure and DNA damage (genotoxicity): systematic review and meta-analysis

Studies suggest that chronic lead (Pb) exposure may induce deoxyribonucleic acid (DNA) damage. However, there is no synthesised evidence in this regard. We systematically reviewed existing literature and synthesised evidence on the association between chronic Pb exposure and markers of genotoxicity. Observational studies reporting biomarkers of DNA damage among occupationally Pb-exposed and unexposed controls were systematically searched from PubMed, Scopus and Embase databases from inception to January 2022. The markers included were micronucleus frequency (MN), chromosomal aberrations, comet assay, and 8-hydroxy-deoxyguanosine. During the execution of this review, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Mean differences in the biological markers of DNA damage between Pb-exposed and control groups were pooled using the random-effects model. The heterogeneity was assessed using the Cochran-Q test and I² statistic. The review included forty-five studies comparing markers of DNA damage between Pb-exposed and unexposed. The primary studies utilised buccal and/or peripheral leukocytes for evaluating the DNA damage. The pooled quantitative results revealed significantly higher DNA damage characterised by increased levels of MN and SCE frequency, chromosomal aberrations, and oxidative DNA damage (comet assay and 8-OHdG) among Pb-exposed than the unexposed. However, studies included in the review exhibited high levels of heterogeneity among the studies. Chronic Pb exposure is associated with DNA damage. However, high-quality, multicentred studies are required to strengthen present observations and further understand the Pb's role in inducing DNA damage. CRD42022286810.

Adsorption of Cd to TiO2-NPs Forms Low Genotoxic AGGREGATES in Zebrafish Cells

The aquatic environment is involved in the pollutants spreading mechanisms, including nanomaterials and heavy metals. The aims of this study were to assess the in vivo genotoxicity of Cd (1 mg/L) and to investigate the genomic effects generated by its co-exposure with TiO₂-NPs (10 µg/L). The study was performed using zebrafish as a model for 5, 7, 14, 21, and 28 days of exposure. The genotoxic potential was assessed by three experimental approaches: DNA integrity, degree of apoptosis, and molecular alterations at the genomic level by genomic template stability (% GTS) calculation. Results showed an increased in DNA damage after Cd exposure with a decrease in % GTS. The co-exposure (TiO₂-NPs + Cd) induced a no statistically significant loss of DNA integrity, a reduction of the apoptotic cell percentage and the recovery of genome stability for prolonged exposure days. Characterization and analytical determinations data showed Cd adsorption to TiO₂-NPs, which reduced free TiO₂-NPs levels. The results of our study suggest that TiO₂-NPs could be used for the development of controlled heavy metal bioremediation systems.

Biomonitoring findings for occupational lead exposure in battery and ceramic tile workers using biochemical markers, alkaline comet assay, and micronucleus test coupled with fluorescence in situ hybridisation

Manufacture of lead-containing products has long been associated with various health risks. To get an insight into the related genotoxic risks, we conducted a biomonitoring study in 50 exposed workers and 48 matched controls using a battery of endpoints that sensitively detect the extent of genome instability in peripheral blood lymphocytes. The levels of primary DNA damage were estimated with the alkaline comet assay, while cytogenetic abnormalities were determined with the cytokinesis-block micronucleus (CBMN) cytome assay. Additionally, CBMN slides of 20 exposed and 16 control participants were subjected to fluorescence in situ hybridisation (FISH), coupled with pancentromeric probes to establish the incidence of centromere-positive micronuclei, nuclear buds, and nucleoplasmic bridges. Blood lead levels (B-Pb) were measured with atomic absorption spectrometry. To further characterise cumulative effects of occupational exposure, we measured erythrocyte protoporphyrin (EP) concentrations and delta-aminolevulinic acid dehydratase (ALAD) activity in blood. We also assessed the influence of serum folate (S-folate) and vitamin B12 (S-B12) on genome stability. Compared to controls, occupationally exposed workers demonstrated significantly higher B-Pb (298.36±162.07 vs 41.58±23.02), MN frequency (18.71±11.06 vs 8.98±7.50), centromere positive MN (C+ MN) (8.15±1.8 vs 3.69±0.47), and centromere negative MN (C- MN) (14.55±1.80 vs 4.56±0.89). Exposed women had significantly higher comet tail intensity (TI) and length (TL) than control women. Furthermore, workers showed a positive correlation between age and nuclear buds and MN, between MN and years of exposure, and between S-B12 levels and TI and ALAD activity, while a negative correlation was found between TI and B-Pb. These findings suggest that occupational settings in the manufacture of lead-containing products pose significant genotoxic risks, which calls for developing more effective work safety programmes, including periodical monitoring of B-Pb and genetic endpoints.

Zinc-protoporphyrin determination by HPLC with fluorescence detection as a biomarker of lead effect in artisanal pottery workers

Lead (Pb) exposure compromises heme synthesis by inhibiting ferrochelatase, forming zinc-protoporphyrin (ZnPP). This study aims to validate a method for the determination of ZnPP by HPLC with fluorescence detection and apply this method to evaluate the extent of Pb exposure of artisanal pottery workers. Extraction procedures were tested using both nonacid and acid liquid-liquid extraction. The former presented a better chromatogram and recovery results. The validated method yielded a good resolution of ZnPP and its free form peaks with acceptable precision and accuracy. Total run time was 15 min and ZnPP peak retention time was 5.6 min. We applied this method to evaluate 39 potters (90% male), mean age 40 years (9-80). The medians (ranges) of blood lead, ZnPP and hemoglobin were 16.0 μg/dl (2.2-71.5), 12.6 μg/dl (4.6-279.8) and 15.1 g/dl (11.0-17.8), respectively. Significant differences were observed for blood lead according to gender, age range (>40 years), direct handling of lead oxide and years of occupation. Significantly higher levels of ZnPP were observed in male potters involved with lead glazing activity. The validated method was shown to be simple with one-step nonacid extraction, good sensitivity, reproducibility and accuracy. Our data shows that these laborers are dangerously exposed to Pb, reflecting the effect on the heme synthesis.

Induction of genotoxicity and mutagenic potential of heavy metals in Thai occupational workers

Heavy metals are widely used in many industries in Thailand and found in the environment. Occupational exposure to heavy metals is often chronic and caused by environmental contaminations, potentially leading to mutations and cancer. Although the genotoxic effects of occupational exposure to multiple heavy metals have been extensively studied, the findings regarding their genotoxicity are conflicting. In this study, we focused on investigating the genotoxic effects of certain heavy metals mixtures, including lead (Pb), copper (Cu), zinc (Zn), and tin (Sn), to which workers are exposed in the manufacturing industry. The cytokinesis-blocked micronucleus (CBMN) assay in peripheral blood lymphocytes was performed, and DNA damage was assessed by measuring tumour-associated protein levels and 8-hydroxy-2'-deoxyguanosine (8-OHdG) generated by oxidative stress that causes cytotoxicity. The occupational exposure group included 110 workers exposed to heavy metal mixtures and 105 matched control subjects. We found statistically significant differences in the blood Pb, Sn, and Cu levels between the exposed workers and the control subjects (p < 0.001). Analysis of micronuclei (MN) in peripheral blood lymphocytes revealed a significantly increased frequency of MN in exposed workers compared with that in control subjects (p<0.05). Non-smoking exposed workers were selected for 8-OHdG formation and mutant p53 tests, and significant differences in the mean plasma 8-OHdG concentration (p < 0.001) were found between the occupational exposure and the control group, but no differences were found in the levels of mutant p53. Thus, chronic exposure to different heavy metals causes genotoxic effects in humans. Furthermore, the CBMN assay and 8-OHdG formation can be used as surrogate biomarkers to identify and monitor groups with higher carcinogenic risk in the early stages of toxicity. In summary, our results indicate that mixtures of heavy metals (Pb, Sn, and Cu) in manufacturing industries pose an elevated health risk due to DNA damage.

Effect of lead on proliferation, oxidative stress and genotoxic damage of 3T3-L1 fibroblasts

Lead (Pb) is an environmental and industrial contaminant that still represents a public health problem. In this paper, we investigated the effect of Pb on proliferation, lipid peroxidation and the number of micronucleated cells in exponentially growing 3T3-L1 fibroblasts, a cell line previously used to evaluate different environmental contaminants. We found that Pb (10 μM or higher) was able to inhibit proliferation of exponentially growing cells after 24-h treatment, which was evaluated by the MTT assay and cell counting in Neubauer chamber, but cell survival was not affected according to the trypan blue exclusion assay. On the other hand, Pb was able to increase lipid peroxidation and the number of micronucleated cells, which are indicative of oxidative stress and genotoxic damage respectively. We also found that removal of Pb after 24-h treatment allowed cells to recover proliferation. Our results indicate that Pb was able to induce oxidative stress and genotoxicity in this cell line under standardized conditions, which supports the involvement of Pb in similar effects observed in human exposed to this heavy metal. In addition, Pb inhibits proliferation of exponentially growing fibroblasts but cells resume proliferation after removal of this metal, which suggests that it is important to move away Pb-exposed individuals from the source of contamination.

The effects of lead on the development of somites in chick embryos (Gallus gallus domesticus) under in vitro conditions: a histological study

Lead (Pb) is one of the most abundant toxic metals in the environment that can cause a variety of harmful effects. During embryonic development of vertebrates, somites are temporary organs that give rise to skeletal muscle, cartilage, tendon, endothelial cells, and dermis. In this study, we investigated the effects of lead on the development of somites and their derivatives in chick embryos under in vitro conditions. For this propose, fertilized eggs of Gallus gallus domesticus were incubated until they reached the stage of 15-20 somites. The somites and notochord were isolated and treated with different concentrations of lead acetate (500, 1000, 2000, and 4000 ng ml-1) for 72 h. Our results indicated that high concentrations of lead reduced the nucleus diameter, reduced the synthesis of collagen, inhibited the formation of the cartilage matrix in somite cells, and disturbed the formation and order of myotubes. In conclusion, the results of the current study for the first time indicated the disturbing effects of lead on the development of somites in the chick embryo. Our results revealed that lead disturbed the development of somites in the chick embryo, which suggested that at high concentrations it can cause a serious mortal danger to life.

Lead Induces Genotoxicity via Oxidative Stress and Promoter Methylation of DNA Repair Genes in Human Lymphoblastoid TK6 Cells

Background

Lead (Pb) is a widely used metal in modern industry and is regarded as a health hazard. Although lead-induced genotoxicity has been confirmed, the direct evidence that lead induces genotoxicity in human cells and its related mechanisms has not been fully elucidated. In this study, for the first time, we evaluated the genotoxicity induced by lead in human lymphoblastoid TK6 cells.

Material/Methods

The TK6 cells were incubated with various concentrations of Pb(Ac)₂ for 6 h, 12 h, or 24 h. Cell viability was detected by CCK8 assay. Various biochemical markers were assessed by specific kits. Immunofluorescence assay was used to detect γ-H2AX foci formation. The promoter methylation was assessed by methylation-specific PCR. The protein levels were determined by Western blot assay.

Results

The results showed that after exposure to lead, cell viability was obviously decreased and γ-H2AX foci formation was significantly enhanced in TK6 cells. Moreover, the levels of 8-OHdG, ROS, MDA, and GSSG were increased, while the GSH level and SOD activity were decreased in lead-treated TK6 cells. The activation of the Nrf2-ARE signaling pathway was involved in lead-induced oxidative stress in TK6 cells. Finally, the expressions of DNA repair genes XRCC1, hOGG-1, BRCA1, and XPD were inhibited via enhancing their promoter methylation in TK6 cells after exposure to lead.

Conclusions

Taken together, our study provides the first published evidence that lead exposure results in DNA damage via promoting oxidative stress and the promoter methylation of DNA repair genes in human lymphoblastoid TK6 cells.

Occupational Health and the Visual Arts: An Introduction

OBJECTIVE

Occupational hazards in the visual arts often involve hazardous materials, though hazardous equipment and hazardous work conditions can also be found. Occupational health professionals are familiar with most of these hazards and are particularly qualified to contribute clinical and preventive expertise to these issues.

METHODS

Articles illustrating visual arts health issues were sought and reviewed. Literature sources included medical databases, unindexed art-health publications, and popular press articles.

RESULTS

Few medical articles examine health issues in the visuals arts directly, but exposures to pigments, solvents, and other hazards found in the visual arts are well described. The hierarchy of controls is an appropriate model for controlling hazards and promoting safer visual art workplaces.

CONCLUSIONS

The health and safety of those working in the visual arts can benefit from the occupational health approach. Sources of further information are available.

Oxidative DNA damage and oxidative stress in lead-exposed workers

There are many discrepancies among the results of studies on the genotoxicity of lead. The aim of the study was to explore lead-induced DNA damage, including oxidative damage, in relation to oxidative stress intensity parameters and the antioxidant defense system in human leukocytes. The study population consisted of 100 male workers exposed to lead. According to the blood lead (PbB) levels, they were divided into the following three subgroups: a group with PbB of 20-35 μg/dL (low exposure to lead (LE) group), a group with a PbB of 35-50 µg/dL (medium exposure to lead (ME) group), and a group with a PbB of >50 μg/dL (high exposure to lead (HE) group). The control group consisted of 42 healthy males environmentally exposed to lead (PbB < 10 μg/dL). A comet assay was used to measure the DNA damage in leukocytes. We measured the activity of superoxide dismutase (SOD), catalase, glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), and glutathione-S-transferase (GST) as well as the concentration of malondialdehyde (MDA), and the value of the total antioxidant capacity. The level of PbB was significantly higher in the examined subgroups than in the control group. The percentage of DNA in the tail was significantly higher in the LE, ME, and HE subgroups than in the control group by 10% ( p = 0.001), 15% ( p < 0.001), and 20% ( p < 0.001), respectively. The activity of GR was significantly lower in the LE and ME subgroups than in the control group by 25% ( p = 0.007) and 17% ( p = 0.028), respectively. The activity of G6PD was significantly lower in the ME subgroup by 25% ( p = 0.022), whereas the activity of GST was significantly higher in the HE subgroup by 101% ( p = 0.001) than in the control group. Similarly, the activity of SOD was significantly higher in the LE and ME subgroups by 48% ( p = 0.026) and 34% ( p = 0.002), respectively. The concentration of MDA was significantly higher in the LE, ME, and HE subgroups than in the control group by 43% ( p = 0.016), 57% ( p < 0.001), and 108% ( p < 0.001), respectively. Occupational lead exposure induces DNA damage, including oxidative damage, in human leukocytes. The increase in DNA damage was accompanied by an elevated intensity of oxidative stress.

Results of micronucleus assays with individuals who are occupationally and environmentally exposed to mercury, lead and cadmium

Millions of humans are exposed occupationally and environmentally to lead, mercury and cadmium compounds. Mercury compounds are less abundant but some of them belong to the most toxic chemicals which are known. We evaluated the literature to find out if these metals act in humans as genotoxic carcinogens and if their health effects can be predicted by use of micronucleus (MN) assays with lymphocytes and/or with other genotoxicity tests. Numerous studies showed that lead and mercury induce cancer in humans and also in animals, in vitro experiments with cultured cells indicate that they cause DNA damage via different molecular mechanisms including release of reactive oxygen species and interactions with DNA repair processes. Also in most human studies, positive results were obtained in MN tests with lymphocytes (all 15 occupational studies with lead yielded positive results, with mercury 6 out of 7 investigations were positive). For cadmium, there is clear evidence that it causes cancer in humans; however, induction of chromosomal damage was only seen in high dose experiments with mammalian cells while results of animal and human studies yielded conflicting results (only in 2 of 5MN trials with humans positive findings were reported). Possibly, non-genotoxic mechanisms such as inhibition of apoptosis and interaction with signaling pathways account for the carcinogenic properties of cadmium species. The findings of MN studies with lead and mercury are in excellent agreement with results which were obtained with other endpoints (e.g. chromosomal aberrations and comet formations) and it is evident that this approach can be used for occupational and environmental monitoring of exposed individuals. Important future tasks will be the realization of larger studies with a uniform standardized protocol, the additional evaluation of anomalies other than MN (nuclear buds and bridges) and the combination of such trials with investigations which allow to define the molecular mechanisms relevant for exposed humans.

Dietary total antioxidant capacity is associated with plasmatic antioxidant capacity, nutrient intake and lipid and DNA damage in healthy women

Dietary total antioxidant capacity (DTAC) seems to be associated with reducing risk of diseases. However, data about the influence of the DTAC on oxidative stress parameters are scarce. The aim of this study was to estimate the DTAC and its influence on plasma total antioxidant capacity (PTAC), and damage to lipids, proteins and DNA in healthy women. It was found a positive correlation between DTAC and PTAC in young and healthy subjects, where presumably the endogenous defenses are fully functional. DTAC and PTAC were positively correlated with the intake of known antioxidants, including vitamin C and polyphenols. The DTAC exhibited a negative correlation with lipid oxidative damage, while PTAC showed a negative correlation with DNA damage. This data contributes to better understanding of the recommended dietary antioxidant intake for promoting health.

Influence of abatement of lead exposure in Croatia on blood lead and ALAD activity

We evaluated the effect of lead (Pb) abatement measures in Croatia on blood lead (BPb) concentrations, and delta-aminolevulinic acid dehydratase (ALAD) activity in blood, as a sensitive indicator of early Pb effect. Data on BPb and ALAD activity were obtained from 829 Croatian men (19-64 years of age), with no known occupational exposure to metals. Data obtained in 2008-2009, after the ban of leaded gasoline in Croatia in 2006, were compared with similar data collected in 1981 and 1989, when the concentration of Pb in gasoline was 0.6 g/L. Our results showed a highly significant (p < 0.001) decrease in median BPb from 114.5 (range, 46.0-275.0) μg/L in 1981/1989 to 30.3 (range, 3.2-140.8) μg/L in 2008-2009 and an increase in median ALAD activity from 49.8 (range, 24.9-79.4) EU in 1981/1989 to 60.9 (range, 35.8-84.0) EU in 2008-2009. Individual factors influencing BPb values were, in the order of decreasing importance, Pb in ambient air (APb), alcohol consumption, age, and smoking. Increased ALAD activity was significantly associated with the decrease of APb, alcohol consumption, and smoking. These results show that lead abatement measures had a positive impact on both BPb concentrations (73.5% decrease) and the activity of ALAD (22.1% increase) in general population. Our results contribute to growing evidence that ALAD activity may be used as one of the earliest and sensitive diagnostic biomarkers of low-level Pb exposure.

Monitoring Genotoxicity Potential in the Mumbuca Stream, Minas Gerais, Brazil

Rivers are sites for water catchment to supply metropolitan areas but also serve as receptors for discharge of urban sewage, wastewater, and agri-industrial effluents. Bioindicators or sentinel organisms are widely used as markers of pollution in various environments. The objective of this study was to evaluate the genotoxic potential and consequent quality of the water from the Mumbuca stream, which supplies the city of Monte Carmelo, located in the Minas Triangle region, Minas Gerais, Brazil. This was achieved using two variable response bioindicators (Rhamdia quelen and Geophagus brasiliensis), the micronucleus (MN) test, and determining the presence of metals by flame atomic absorption spectrometry. Results showed that site 3 water (region of residential flow and intense industrial pottery activity) presented a greater possibility for induction of genotoxic activity, as evidenced by the increase in the MN frequency in Rhamdia quelen and Geophagus brasiliensis in comparison with the reference-site water. The water of the Mumbuca stream was influenced by genotoxic agents, especially lead and chromium, assessed by the rise in MN rate. Data suggested that discharge of industrial effluents in a specific stretch of the stream interfered with biota functions.

Assessment of genotoxic effects of lead in occupationally exposed workers

The genotoxicological effects in 200 lead acid storage battery recycling and manufacturing industry workers in Hyderabad along with matched 200 controls were studied. The genetic damage was determined by comet, micronucleus (MN), and chromosomal aberration (CA) test in peripheral blood lymphocytes (PBL). The MN test was also carried out in buccal epithelial cells (BECs). Pb in ambient air, blood Pb (B-Pb) concentrations, and hematological parameters were measured. The superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) formed were also studied. The results of the present study showed that there was a statistically significant (P < 0.01) increase in mean percent tail DNA, frequency of CA, and MN in PBL as well as in BEC as compared to controls. Pb in ambient air and B-Pb concentrations were found to be significantly higher (P < 0.01). The hematocrit, hemoglobin, and red blood cell values were significantly lowered in Pb-exposed workers in comparison to controls. SOD, GPx, and CAT levels were significantly decreased while GSH and MDA levels increased in exposed group when compared to control group. The present study suggests that environmental health standards should be enforced to control Pb contamination from battery industries to reduce human health risk.

Reproductive toxicity of lead, cadmium, and phthalate exposure in men

Environmental toxicants viz lead or cadmium and phthalate esters (di(2-ethylhexyl) phthalate [DEHP], dibutyl phthalate [DBP], and diethyl phthalate [DEP]) widely found in different environmental strata are linked to deteriorating male reproductive health. The objective was to assess the relationships between the seminal lead, cadmium, and phthalate (DEHP, DBP, DEP) concentrations at environmental level and serum hormone levels and semen quality in non-occupationally exposed men and specify the effect of individual and combined exposure of toxicants on semen quality. A study of 60 male partners of couples attending the Andrology Laboratory of the Reproductive Biology Department, All India Institute of Medical Sciences (AIIMS), New Delhi, India for semen analysis to assess their inability to achieve a pregnancy was selected for the study. The results of univariate and stepwise multiple regression analysis in the unadjusted model showed a significant correlation between lead or cadmium and phthalates DEHP/DBP/DEP and sperm motility, sperm concentration, and DNA damage. After adjusting for potential confounders, an association with lead or DEHP was only observed. The present data shows that lead (Pb) or cadmium (Cd) or phthalates might independently contribute to decline in semen quality and induce DNA damage. Phthalates might influence reproductive hormone testosterone. These findings are significant in light of the fact that men are exposed to a volley of chemicals; however, due to the small sample size, our finding needs to be confirmed in a larger population.

Comparing the metal concentration in the hair of cancer patients and healthy people living in the malwa region of punjab, India

The cancer prevalence in the Malwa region of Punjab (1089/million/year) is much higher than the national average cancer prevalence in India (800/million/year). The participants in the present study were 50 healthy individuals and 49 cancer patients all living in the Malwa region of Punjab, with the healthy people being selected from the same household as the cancer patients. High concentrations of several potentially toxic elements were found in hair samples from people living in Punjab. Compared to standard reference ranges, the metals in excess in both the control and patient groups were aluminium (Al), barium (Ba), manganese (Mn), strontium (Sr) and uranium (U). The most significant findings were high lead (Pb), U and Ba concentrations. The maximum values for Ba, Mn, Pb and U were found in hair from breast cancer patients. The mean concentration of U in hair from the breast cancer patients was 0.63 μg U/g, which is more than double the value found in the control group and over six times higher than the reference range of 0.1 μg U/g. Water, soil, and phosphate fertilizers all seem to play a potential role, causing an increased metal burden in Punjabi people living in the Malwa region. The present study indicates that metals, and especially U, may be a factor in the development of breast cancer among Punjabi women.

Tracking blood lead and zinc protoporphyrin levels in Andean adults working in a lead contaminated environment

The purpose of this study was to investigate current blood lead (PbB) and zinc protoporphyrin (ZPP) levels in adults presently living in environmentally Pb-contaminated Andean communities, and to compare the findings with the PbB and ZPP levels of Pb-exposed adult cohorts from the same study area tested between 1996 and 2007. Blood samples from 39 adults were measured for PbB and ZPP concentrations. The current mean PbB level (22.7 μg/dl) was significantly lower than the mean (37.9 μg/dl) of the initial 1996 cohort. PbB levels for the 1997, 1998, 2003, and 2006 cohorts were also significantly lower than the levels for the 1996 group. Elevated ZPP/heme ratios of 103.3, 128.4, and 134.2 μmol/mol were not significantly different for the 2006, 2007, and 2012 groups, indicating chronic Pb exposure. While ZPP levels of Andean Ecuadorian Pb-glazing workers have remained elevated, PbB levels declined. Lead exposure of the workers needs to be continually monitored.