Children exposure to trace levels of heavy metals at the north zone of Kifissos River

Exploring microplastic pollution in a Mediterranean river: The role of introduced species as bioindicators

Studies of plastic contamination in freshwater ecosystems and their biota remain scarce, despite the fact that the vast majority of plastic waste initially passes through lotic ecosystems. Biomonitoring provides valuable information regarding plastic pollution and microplastic threats to biota and human health. The aim of this study was to explore the potential use of a non-indigenous fish species as a bioindicator of microplastic pollution in an Eastern Mediterranean River. Our study area is located in a heavily modified and vastly impacted urban river which flows through the largest part of the Metropolitan area of Athens, Greece. We used an introduced chub species (Squalius vardarensis) to assess microplastic ingestion in the river. The results indicated moderate occurrence and abundance of microplastics in the fish gastrointestinal tracts; one-third of specimens (35%) contained microplastics, although the average number of microplastics per specimen was relatively low (1.7 ± 0.2). Overall, the abundance of microplastics in the water confirmed the moderate level of microplastics contamination in our study area. The major polymer types of microplastics identified by FT-IR analysis were: polyethylene (PE), polyvinyl alcohol (PVA) and polypropylene (PP); reflecting the fragmentation of larger litter from industrial packaging and/or household goods. Surface runoff of the urban environment, via motorways and major road networks, could be the contributing factor to the reported microplastics. Our results suggest that generalist's non-indigenous species such as chubs could be used as bioindicators of microplastics in inland waters. Introduced fishes can be a feasible, nondestructive, and cost-effective option for the assessment of microplastics in freshwater ecosystems, while freshwater chubs' high abundance and omnipresence in European rivers further serve this scope. However, it is worth noting that the suitability of any particular species as a bioindicator of microplastics may depend on a variety of factors, including their feeding behavior, habitat, and exposure to microplastics in their environment.

Levels of trace elements in human hair samples of adolescents living near petrochemical plants

The aim of the study is a comparative analysis to investigate human hair metal profiles of adolescents residing near petrochemical plants (Sicily, Italy). We selected the small town of Augusta, Gela, and Pace del Mela, and a control area made up of the towns characterized by low anthropogenic activity. Twenty trace elements were measured in samples of scalp hair from adolescents (11-14 years old) of both genders. Hair samples were cleaned using a rigorous cleaning method, mineralized, and processed for analyses by inductively coupled plasma-mass spectrometry (ICP-MS). In industrial sites, zinc was always the most abundant element, ranging from186 to 217 μg g^-1. Following zinc, the elements Al, Ba, Cu, Fe, and Sr were in the range 1-20 μg g^-1. The remaining elements had concentrations < 1 μg g^-1. The comparison with adolescents living in suburban area highlighted that As, Ba, Mn, Sr, U, and V have the highest median concentrations in an industrial location. An industrial factor (As, Mn, Sr, U, and V) and an urban factor (Cd, Cr, Cu, Mo, Ni, and Sb) were distinguished by the multivariate statistical analysis between a cohort residing in urban and industrial areas. Statistically significant differences (Kruskal-Wallis test, p < 0.05) between the genders were found for Ba, Mn, Ni, Sr, and V in all industrial sites with median concentrations higher in females' hair than males'. The data confirm that the study areas are heavily affected by industrial and urban emissions of metals and metalloids, representing a potential hazard to the local population.

Heavy Metal Concentrations in Malaysian Adults' Hair and Associated Variables in Bukit Mertajam, Penang, Malaysia

The presence of heavy metals in human hair is being tracked to predict health risk, forensics, and environmental monitoring. Heavy metals are typically non-biodegradable and have a lengthy half-life, allowing them to linger in humans and the environment for many years. Heavy metal exposure in hair has been attributed to multiple sources from the environment and food intake. In this study, copper (Cu), nickel (Ni), zinc (Zn), chromium (Cr), manganese (Mn), lead (Pb), and cadmium (Cd) levels were measured in the scalp hair of 50 individuals in Bukit Mertajam, Penang, Malaysia. In conjunction with sampling, subjects' age, gender, lifestyle, diet, and working environment were also obtained through the questionnaire. The Atomic Absorption Spectrometry (AAS) method was used to extract all the metals in the hair samples. The mean concentrations of heavy metals were found to be in the following order (unit of mg/kg): Cr > Zn > Pb > Ni > Cd > Cu. Manganese was detected below the limit of quantitation among the elements (< LOQ). All elements except Mn were higher and comparable to the previous studies' international limit values. Cadmium prevalence was substantially associated with age, smoking habit, dyed hair, and working environment in Pearson's correlation analysis (p ≤ 0.05). Zinc was also found to be related to the working environment. Some elements were observed to be statistically related between heavy metals, Cd/Zn, Cd/Ni, Cr/Ni, and Pb/Ni, whereas smoking habit/dyed hair and dyed hair/working environment were the associated factors for metal distribution that were statistically correlated (p ≤ 0.05). To recapitulate, this study found that the distribution of heavy metals in hair was influenced by associated factors and between heavy metals. It has been indicated that heavy metal exposure to humans is influenced by factors such as geographical location, lifestyle, and working environment.

Lead (Pb) and neurodevelopment: A review on exposure and biomarkers of effect (BDNF, HDL) and susceptibility

Lead (Pb) is a ubiquitous environmental pollutant and a potent toxic compound. Humans are exposed to Pb through inhalation, ingestion, and skin contact via food, water, tobacco smoke, air, dust, and soil. Pb accumulates in bones, brain, liver and kidney. Fetal exposure occurs via transplacental transmission. The most critical health effects are developmental neurotoxicity in infants and cardiovascular effects and nephrotoxicity in adults. Pb exposure has been steadily decreasing over the past decades, but there are few recent exposure data from the general European population; moreover, no safe Pb limit has been set. Sensitive biomarkers of exposure, effect and susceptibility, that reliably and timely indicate Pb-associated toxicity are required to assess human exposure-health relationships in a situation of low to moderate exposure. Therefore, a systematic literature review based on PubMed entries published before July 2019 that addressed Pb exposure and biomarkers of effect and susceptibility, neurodevelopmental toxicity, epigenetic modifications, and transcriptomics was conducted. Finally included were 58 original papers on Pb exposure and 17 studies on biomarkers. The biomarkers that are linked to Pb exposure and neurodevelopment were grouped into effect biomarkers (serum brain-derived neurotrophic factor (BDNF) and serum/saliva cortisol), susceptibility markers (epigenetic markers and gene sequence variants) and other biomarkers (serum high-density lipoprotein (HDL), maternal iron (Fe) and calcium (Ca) status). Serum BDNF and plasma HDL are potential candidates to be further validated as effect markers for routine use in HBM studies of Pb, complemented by markers of Fe and Ca status to also address nutritional interactions related to neurodevelopmental disorders. For several markers, a causal relationship with Pb-induced neurodevelopmental toxicity is likely. Results on BDNF are discussed in relation to Adverse Outcome Pathway (AOP) 13 ("Chronic binding of antagonist to N-methyl-D-aspartate receptors (NMDARs) during brain development induces impairment of learning and memory abilities") of the AOP-Wiki. Further studies are needed to validate sensitive, reliable, and timely effect biomarkers, especially for low to moderate Pb exposure scenarios.

Effects of soil lead exposure and land use characteristics on neurodevelopment among children under 3 years of age in northern Taiwan

Lead (Pb) exposure increases the risks of neurodevelopmental disorders in children. Child-specific activities and land use scenarios may lead to elevated opportunities for Pb exposure through the soil. Therefore, we investigated hair and fingernail Pb concentrations among young children in northern Taiwan, in relation to soil Pb pollution and land use characteristics. We also explored the effect of the Pb exposure burden and land use scenarios on neurobehavioral development. In total, 139 healthy children under 3 years of age were recruited in October 2011 to April 2014. Pb levels in hair and fingernail samples were determined using an inductively coupled plasma/mass spectrometer. Pb concentrations in soils and land use types surrounding the children's homes were accessed by a geographic information system to identify any associations with hair Pb levels. The Bayley Scales of Infant and Toddler Development (Bayley-III) were used to evaluate the cognitive, language, and motor development of the children. A multivariable regression model was performed to assess the effects of soil Pb levels and land-use status on Pb exposure in children, as well as associations of Pb exposure and land-use scenarios with neurodevelopmental abilities. Geometric mean Pb concentrations in hair, fingernails, and soil were 2.9 ± 4.8 μg/g, 0.8 ± 5.1 μg/g, and 20.8 ± 4.3 mg/kg, respectively. The multivariable analysis indicated that soil Pb concentrations and green areas around residences had potential links with Pb exposure among children in northern Taiwan. Hair Pb concentrations were negatively associated with expressive language scores. Soil Pb exposure was positively associated with hair Pb concentrations. Land use types around the children's homes in northern Taiwan were associated with their neurodevelopment. Increased green areas were negatively associated with hair Pb concentrations. Living near a highway may have had negative impacts on gross motor scores. A healthy residence can avoid potential health risks for children during their early life.

Element Levels and Predictors of Exposure in the Hair of Ethiopian Children

Children's development and health may be affected by toxic heavy metal exposure or suboptimal essential element intake. This study aimed to provide updated information regarding the concentrations of 41 elements in children's hair (aged under 18) living in a rural area of the Benishangul-Gumuz region, Ethiopia. The highest average levels (as a geometric mean) for toxic heavy metals were obtained for Al (1 mg kg^-1), Pb (3.1 mg kg^-1), and Ni (1.2 mg kg^-1), while the lowest concentrations among the essential elements were found for Co (0.32 mg kg^-1), Mo (0.07 mg kg^-1), Se (0.19 mg kg^-1), and V (0.8 mg kg^-1). Hair analysis was combined with a survey to evaluate relationships and variations among subgroups and potential metal exposure predictors. Females showed significantly higher concentrations for most hair elements, excluding Zn, than males, and the 6-11 years age group reported the highest levels for Be, Ce, Co, Fe, La, Li, Mo, and Na. The main predictors of exposure to toxic elements were fish consumption for Hg and drinking water for Ba, Be, Cs, Li, Ni, Tl, and U. The data from this study can be used to develop prevention strategies for children's health and protection in developing countries.

Trace Elements in Blood of the Population Living near a Hazardous Waste Incinerator in Catalonia, Spain

In 2012, the concentrations of trace elements (As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl, and V) were measured in blood samples of the population living in the vicinity of a hazardous waste incinerator (HWI) located in Tarragona County (Catalonia, Spain). This study is part of a wide surveillance program aimed at assessing the impact of the facility on the public health conducted since 1998, before the HWI started operating. Lead was the metal occurring with the highest concentration (21.7 μg kg^-1), followed by Mn (19.7 μg kg^-1) and Hg (4.62 μg kg^-1). Arsenic (6.99 μg kg^-1) showed a low detection rate (49%), while the rest of the analyzed trace elements were not detected. In 2017, a new sampling campaign was conducted, and three new trace elements (Co, Cu, and Sb) were added. In the most recent survey, Cu reached a mean concentration of 931 μg kg^-1, up to 60-fold higher than that corresponding to the remaining trace elements. Relatively high levels were also found for Sb (16.0 μg kg^-1), Mn (13.9 μg kg^-1), and Pb (13.0 μg kg^-1). In comparison with the baseline study (1998), Hg, Mn, and Pb significantly decreased over time. Some trace elements showed significant differences according to sex, age, and area of residence. In general, the concentrations of trace elements in blood were similar to, or even lower than, those reported in the scientific literature. Hence, the exposure to trace elements does not mean any additional health risk for the population living near the HWI. This conclusion is in agreement with other studies carried out in the framework of this surveillance program, in which trace elements have been measured in different biological matrices, such as hair and autopsy tissues (brain, bone, kidney, liver, and lungs).

Biomonitoring of Trace Elements in Hair of Schoolchildren Living Near a Hazardous Waste Incinerator-A 20 Years Follow-Up

Since 1998, a monitoring program is periodically performed to assess the environmental and human health impact of air chemicals potentially emitted by a hazardous waste incinerator (HWI) located in Constantí (Catalonia, Spain). In 2017, samples of hair were collected from 94 schoolchildren (aged 10-13 years) living nearby and the levels of 11 trace elements (As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl and V) were determined. The concentrations showed the following descending order: Pb > Hg > Ni > Sn > Mn > Cr. In turn, As, Be and Tl were not detected, while Cd and V were found only in a few samples. Some metal levels were significantly, positively correlated. Some significant differences were also noticed according to the gender and the specific zone of residence. Finally, the levels of trace elements showed fluctuations through time. Cr and Pb showed a significant decrease in comparison to the concentrations obtained in the baseline study (1998). According to the current results, metal emissions from the HWI are not relevant in terms of human health impact since their levels were similar and even lower than those reported in other contaminated areas.

Metals in biological tissues of the population living near a hazardous waste incinerator in Catalonia, Spain: Two decades of follow-up

During the period 1996-1998, a hazardous waste incinerator (HWI) was built in Constantí (Tarragona County, Catalonia, Spain). Because of the potential adverse effects of toxic emissions, mainly metals and dioxins and furans, waste incinerators in general have been an important cause of concern for the public opinion. For that reason, to assess its environmental impact on the surroundings, as well as the potential human health risks of the HWI, environmental and biological monitoring studies have been carried out since 1996-1998, when the baseline concentrations were established. This article summarizes all the results corresponding to metals in biological tissues of the population living near the HWI, two decades after the construction of the facility. In 1996-1998, the baseline concentrations of a number of elements (As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl and V) were determined in samples of hair, blood and autopsy tissues (bone, brain, liver, lung and kidney) of subjects living in the area. In successive 5-year periods, new surveys were conducted to periodically measure the levels of metals in the same biological tissues. The daily dietary intake of these metals was also estimated for the population of the area. The results of this surveillance program do no suggest additional adverse health risks of metals for the population living near the HWI. However, special attention should be paid to Cr, due not only to the increases of this element observed in most analyzed biological tissues, but also in its dietary intake.

Determinants of Hair Manganese, Lead, Cadmium and Arsenic Levels in Environmentally Exposed Children

Biomarkers of environmental metal exposure in children are important for elucidating exposure and health risk. While exposure biomarkers for As, Cd, and Pb are relatively well defined, there are not yet well-validated biomarkers of Mn exposure. Here, we measured hair Mn, Pb, Cd, and As levels in children from the Mid-Ohio Valley to determine within and between-subject predictors of hair metal levels. Occipital scalp hair was collected in 2009-2010 from 222 children aged 6-12 years (169 female, 53 male) participating in a study of chemical exposure and neurodevelopment in an industrial region of the Mid-Ohio Valley. Hair samples from females were divided into three two centimeter segments, while males provided a single segment. Hair was cleaned and processed in a trace metal clean laboratory, and analyzed for As, Cd, Mn, and Pb by magnetic sector inductively coupled plasma mass spectrometry. Hair Mn and Pb levels were comparable (median 0.11 and 0.15 µg/g, respectively) and were ~10-fold higher than hair Cd and As levels (0.007 and 0.018 µg/g, respectively). Hair metal levels were higher in males compared to females, and varied by ~100-1000-fold between all subjects, and substantially less (<40-70%) between segments within female subjects. Hair Mn, Pb, and Cd, but not As levels systematically increased by ~40-70% from the proximal to distal hair segments of females. There was a significant effect of season of hair sample collection on hair Mn, Pb, and Cd, but not As levels. Finally, hair metal levels reported here are ~2 to >10-fold lower than levels reported in other studies in children, most likely because of more rigorous hair cleaning methodology used in the present study, leading to lower levels of unresolved exogenous metal contamination of hair.

Secondhand smoke is associated with heavy metal concentrations in children

Secondhand smoke (SHS) has adverse effects on health, particularly for children. Our purpose was to analyze the correlation between SHS exposure and heavy metal concentrations in children. The investigation was conducted in Xinxiang County, Henan Province, China, from August 2015 to December 2015. In total, 821 students (433 boys and 388 girls) were recruited, and the contents of heavy metals in their hair-including chromium, manganese, nickel, arsenic, lead, and cadmium-were detected by ICP-MS. The children's parents were informed, and a questionnaire was conducted, which included questions about smoking habits and demographic characteristics. Our results indicate that all parent smokers are fathers, 48.9% of fathers who are smokers, but 25.2% of fathers smoke in front of their children. The levels of chromium (median girls vs boys, μg/g) (2.36 vs 2.06, p < 0.001), nickel (1.28 vs 0.97, p < 0.001), arsenic (0.55 vs 0.49, p < 0.001), and lead (2.73 vs 2.16, p < 0.001) in girls were significantly higher than in boys. The levels of cadmium (median, SHS group vs control: 0.43 vs 0.29 (μg/g), p < 0.001) and lead (median, SHS group vs control: 2.71 vs 2.27 (μg/g), p = 0.007) in the SHS group were significantly higher than in the control. Multi-linear regression analysis indicated that SHS exposure in children is very likely to be correlated with increasing levels of lead (β (95% CI): 0.53 (0.99-5.14), p = 0.023) and cadmium (β (95% CI): 0.43 (0.14-0.73), p = 0.003) in their hair. In conclusion, children exposed to SHS have increased lead and cadmium accumulations in the body.

CONCLUSION

In our study, 821 students (433 boys and 388 girls) were recruited, and the contents of heavy metals in their hair-including chromium, manganese, nickel, arsenic, lead, and cadmium-were detected by ICP-MS. And the secondhand smoking (SHS) exposure was inquired by face-to-face investigation of their parents. We illustrated that children exposed to SHS have increased lead and cadmium accumulations in the body. What is Known: • Secondhand smoke (SHS) has adverse effects on health, particularly for children. • There might be correlation between SHS exposure and heavy metal concentrations in children. What is New: • The levels of chromium, nickel, arsenic, and lead in girls were significantly higher than in boys. • SHS exposure in children was correlated with increasing levels of lead and cadmium in their hair because of exposure to SHS.

Gender as a key factor in trace metal and metalloid content of human scalp hair. A multi-site study

This multi-site study discusses the content of metals and metalloids (MM) in scalp hair of children, living in different environmental contexts, with the purpose of verifying if hair level of some MM is distinctively gender-specific. A total of 943 hair samples (537 females and 406 males) from adolescents were analyzed for their content of Al, As, Ba, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn. Elemental quantification was performed by ICP-MS. The obtained data identified different metal distributions in adolescent girls which exhibited significantly higher hair concentrations of some trace metals, especially Sr, Zn and Ni, than boys. On the base of the median value, hair of female donors contained 3.8 times more Sr (6.6μg/g) than males (1.7μg/g). Highest concentrations of Zn in females were observed in samples from the mining area of Sardinia (587μg/g). Nickel showed significant differences resulting 2.5-fold higher in female hair. Regardless of the residence site, these elements resulted always significantly different (at p<0.01) between female and male indicating that gender is a confounding factor that has to be more extensively considered for a correct interpretation of metal profiles in human hair.

Assessment of environmental and occupational exposure to heavy metals in Taranto and other provinces of Southern Italy by means of scalp hair analysis

The monitoring of heavy metals in industrialized areas to study their association with different occupational and environmental factors is carried out in different ways. In this study, scalp hair analysis was used for the assessment of exposure to these metals in the industrial city of Taranto, characterized by a severe environmental pollution. The highest median values were observed for aluminum, barium, cadmium, lead, mercury, and uranium. Moreover, in the industrial area of Taranto, high levels of barium, cadmium, lead, mercury, nickel, and silver were observed in comparison with other Apulia areas. The risk odds ratios (ORs) for observing values above the 50th percentile were elevated for mercury and fish consumption, uranium and milk consumption, lead and female sex, and aluminum and mineral water consumption. No significant increased risk was observed for occupational activities. In a dendrogram of a cluster analysis, three clusters were observed for the different areas of Taranto (Borgo, San Vito, and Statte). A scree plot and score variables plot underline the presence of two principal components: the first regarding antimony, lead, tin, aluminum and silver; the second regarding mercury and uranium. The observed clusters (Borgo, San Vito, and Statte) showed that lead, antimony, tin, aluminum, and silver were the main component. The highest values above the 50th percentile of these minerals, especially lead, were observed in the Borgo area. The observed metal concentration in the Borgo area is compatible with the presence in Taranto of a military dockyard and a reported increase of lung cancer risk among residents of that area.

Penalized linear discriminant analysis and Discrete AdaBoost to distinguish human hair metal profiles: The case of adolescents residing near Mt. Etna

The research focus of the present paper was twofold. First, we tried to document that human intake of trace elements is influenced by geological factors of the place of residence. Second, we showed that the elemental composition of human hair is a useful screening tool for assessing people's exposure to potentially toxic substances. For this purpose, we used samples of human hair from adolescents and applied two robust statistical approaches. Samples from two distinct geological and environmental sites were collected: the first one was characterized by the presence of the active volcano Mt. Etna (ETNA group) and the second one lithologically made up of sedimentary rocks (SIC group). Chemical data were statistically processed by Penalized Linear Discriminant Analysis (pLDA) and Discrete AdaBoost (DAB). The separation between the two groups turned out well, with few overlaps accounting for less than 5%. The chemical variables that better distinguished ETNA group from SIC group were As, Cd, Co, Li, Mo, Rb, Sr, U and V. Both pLDA and DAB allowed us to characterize the elements most closely related to the volcanic contribution (As, U and V) and those (Cd, Co, Li, Mo, Rb and Sr) prevalently influenced by the geology of the area where SIC samples were collected. We conclude that the geological characteristics of the area of residence constitute a key factor in influencing the potential exposure to trace elements. Hair analysis coupled with robust statistical methods can be effectively used as a screening procedure to identify areas at great environmental risk.

Biomonitoring of arsenic, cadmium, lead, manganese and mercury in urine and hair of children living near mining and industrial areas

Huelva (South West Spain) and its surrounding municipalities represent one of the most polluted estuaries in the world owing to the discharge of mining and industrial related pollutants in their proximity. A biomonitoring study was conducted to assess exposure to arsenic and some trace metals (cadmium, mercury, manganese and lead) in urine and scalp hair from a representative sample of children aged 6-9 years (n=261). This is the only study simultaneously analyzing those five metal elements in children urine and hair. The potential contribution of gender, water consumption, residence area and body mass index on urinary and hair metal concentrations was also studied. Urine levels of cadmium and total mercury in a proportion (25-50%) of our children population living near industrial/mining areas might have an impact on health, likely due to environmental exposure to metal pollution. The only significant correlation between urine and hair levels was found for mercury. Children living near agriculture areas showed increased levels of cadmium and manganese (in urine) and arsenic (in hair). In contrast, decreased urine Hg concentrations were observed in children living near mining areas. Girls exhibited significantly higher trace metal concentrations in hair than boys. The greatest urine arsenic concentrations were found in children drinking well/spring water. Although human hair can be a useful tool for biomonitoring temporal changes in metal concentrations, levels are not correlated with those found in urine except for total mercury, thus providing additional information.

Monitoring lead in hair of children and adolescents of Alcalá de Henares, Spain. A study by gender and residential areas

In recent years there has been an increased interest from the European Union (EU) in the development of large Human Bio-monitoring (HBM) studies across Europe, especially biomonitoring toxic metals. In Spain, most studies using hair as a biomarker have been conducted to determine occupational or industrial exposures, and have involved adult populations. Few studies have involved adolescents and children, despite these groups being sensitive to environmental contamination and pollutants. Therefore, the objective of the present study was to determine the degree of lead exposure in children and adolescents residing in Alcalá de Henares, Spain. Lead poisoning is the number one toxicological threat in the environment. So, lead (Pb) was selected as it is a persistent environmental contaminant, is measureable and is also a neurotoxin that can affect brain development. The city of Alcalá de Henares was divided into four zones to determine the influence of residence area on Pb levels. A range of other variables including age and gender were also considered within the study. The study comprised 115 children (6-9 years old) and 96 adolescents (13-16 years old). There was a significant difference between the levels of Pb in the hair of adolescents, for different gender and area of residence (p<0.001 and p<0.01 respectively). There was no significant difference in the Pb levels in hair of children, for different gender or area of the city. The levels of Pb were significantly (p<0.001) elevated in children compared to adolescents (1.48 vs. 0.70 μg/g), and there was a significant difference in Pb levels in male and female adolescent hair (0.53 vs. 0.77 μg/g) (p<0.001). The association observed between areas of residence and the Pb level in hair of the adolescent group could be mainly attributed to dietary habits and/or socioeconomic status.

Evaluation of toxic metals and essential elements in children with learning disabilities from a rural area of southern Brazil

Children’s exposure to metals can result in adverse effects such as cognitive function impairments. This study aimed to evaluate some toxic metals and levels of essential trace elements in blood, hair, and drinking water in children from a rural area of Southern Brazil. Cognitive ability and δ-aminolevulinate dehydratase (ALA-D) activity were evaluated. Oxidative stress was evaluated as a main mechanism of metal toxicity, through the quantification of malondialdehyde (MDA) levels. This study included 20 children from a rural area and 20 children from an urban area. Our findings demonstrated increase in blood lead (Pb) levels (BLLs). Also, increased levels of nickel (Ni) in blood and increase of aluminum (Al) levels in hair and drinking water in rural children were found. Deficiency in selenium (Se) levels was observed in rural children as well. Rural children with visual-motor immaturity presented Pb levels in hair significantly increased in relation to rural children without visual-motor immaturity (p < 0.05). Negative correlations between BLLs and ALA-D activity and positive correlations between BLLs and ALA-RE activity were observed. MDA was significantly higher in rural compared to urban children (p < 0.05). Our findings suggest that rural children were co-exposed to toxic metals, especially Al, Pb and Ni. Moreover, a slight deficiency of Se was observed. Low performance on cognitive ability tests and ALA-D inhibition can be related to metal exposure in rural children. Oxidative stress was suggested as a main toxicological mechanism involved in metal exposure.

Exposure to mercury among Spanish preschool children: trend from birth to age four

The purpose of this study is to describe the total hair mercury concentrations and their determinants in preschool Spanish children, as well as to explore the trend in mercury exposure from birth to the age four. This evolution has been scarcely studied in other birth cohort studies. The study population was 580 four year old children participating in the INMA (i.e. Childhood and Environment) birth cohort study in Valencia (2008-2009). Total mercury concentration at age four was measured in hair samples by atomic absorption spectrometry. Fish consumption and other covariates were obtained by questionnaire. Multivariate linear regression models were conducted in order to explore the association between mercury exposure and fish consumption, socio-demographic characteristics and prenatal exposure to mercury. The geometric mean was 1.10 µg/g (95%CI: 1.02, 1.19). Nineteen percent of children had mercury concentrations above the equivalent to the Provisional Tolerable Weekly Intake proposed by WHO. Mercury concentration was associated with increasing maternal age, fish consumption and cord blood mercury levels, as well as decreasing parity. Children whose mothers worked had higher mercury levels than those with non working mothers. Swordfish, lean fish and canned fish were the fish categories most associated with hair mercury concentrations. We observed a decreasing trend in mercury concentrations between birth and age four. In conclusion, the children participating in this study had high hair mercury concentrations compared to reported studies on children from other European countries and similar to other countries with high fish consumption. The INMA study design allows the evaluation of the exposure to mercury longitudinally and enables this information to be used for biomonitoring purposes and dietary recommendations.

Trace elements in scalp hair of children chronically exposed to volcanic activity (Mt. Etna, Italy)

The aim of this survey was to use scalp hair as a biomonitor to evaluate the environmental exposure to metals and metalloids of schoolchildren living around the Mt. Etna area, and to verify whether the degree of human exposure to trace elements is subject to changes in local environmental factors. Twenty trace elements were determined in 376 samples of scalp hair from schoolboys (11-13 years old) of both genders, living in ten towns located around the volcanic area of Mt. Etna (Sicily). The results were compared with those (215 samples) from children living in areas of Sicily characterized by a different geological setting (reference site). As, U and V showed much higher concentrations at the volcanic site whereas Sr was particularly more abundant at the reference site. Linear Discriminant Analysis (LDA) indicated an Etna factor, made up of V, U and Mn, and a second factor, concerning the reference site, characterized by Ni and Sr, and to a lesser extent by Mo and Cd. Significant differences in element concentrations were also observed among three different sectors of Mt. Etna area. Young people living in the Mt. Etna area are naturally exposed to enhanced intakes of some metals (V, U, Mn) and non-metals (e.g., As) than individuals of the same age residing in other areas of Sicily, characterized by different lithologies and not influenced by volcanic activity. The petrographic nature of local rocks and the dispersion of the volcanic plume explain the differences, with ingestion of water and local food as the most probable exposure pathways.