An updated systematic review on the association between Cd exposure, blood pressure and hypertension.

BACKGROUND: Since the first report by Perry et al. (1955), most studies affirmed the hypertensive effects of cadmium (Cd) in humans. Nonetheless, conclusions between studies remain inconsistent. OBJECTIVE: The aim of this study was to reevaluate the evidence for a potential relationship between Cd exposure and altered blood pressure and/or hypertension, focusing on studies published between January 2010 and March 2020. METHODS: We reviewed all observational studies from database searches (PubMed and SCOPUS) on Cd exposure and blood pressure or hypertension. We extracted information from studies that provided sufficient data on population characteristics, smoking status, exposure, outcomes, and design. RESULTS: Thirty-eight studies met our inclusion criteria; of those, twenty-nine were cross sectional, three case control, five cohort and one interventional study. Blood or urinary Cd levels were the most commonly used biomarkers. CONCLUSIONS: A positive association between blood Cd levels and blood pressure and/or hypertension was identified in numerous studies at different settings. Limited number of representative population-based studies of never-smokers was observed, which may have confounded our conclusions. The association between urinary Cd and blood pressure and/or hypertension remains uncertain due to conflicting results, including inverse relationships with lack of strong mechanistic support. We point to the urgent need for additional longitudinal studies to confirm our findings.

Blood cadmium levels and sources of exposure in an adult urban population in southern Brazil.

BACKGROUND: Cadmium (Cd) is a toxic metal that is widely present in the environment due to geologic and anthropogenic sources. Exposures to high Cd levels may cause nephrotoxicity, carcinogenicity, pulmonary and cardiovascular disease, among others. The goal of this study was to investigate in an adult urban population whether an association exists between sources and levels of Cd exposure and blood Cd concentrations. METHODS: Using a census-based design, a total of 959 adults, aged 40 years or older, were randomly selected. Information on socio-demographics, dietary, and lifestyle background was obtained by household interviews. Blood Cd levels were measured by inductively coupled-plasma mass spectrometry. Geometric means (GM) (95% CI) and the 50th percentile were determined, stratified by sex, age, race, education, income class, smoking status, consumption of vegetables, red meat and milk, occupation and blood pressure. To assess the association between Cd exposure and the aforementioned variables, we estimated the geometric mean ratio (GMR) (95%CI) of blood Cd concentrations. RESULTS AND CONCLUSION: The geometric mean (95%CI) of blood Cd levels in the total population was 0.25 (0.22, 0.27) ug/dL. In a univariate analysis, significantly higher blood Cd levels were found in men (p < 0.001), current and former smokers (p < 0.001), alcohol drinkers (p < 0.001), those who never or almost never consumed milk (p < 0.001), and in subjects with higher diastolic blood pressure (p = 0.03). Significant correlations were found between the number of cigarettes consumed daily and blood Cd levels. Multivariate analysis confirmed higher blood Cd concentrations were associated with alcohol consumption (GMR 95%CI = 1.28, 1.04-1.59) and in former and current smokers (GMR 95% IC = 1.33, 1.06-1.67 and 4.23, 3.24-5.52, respectively). Our results shed novel information on variables associated with blood Cd levels in an urban Brazilian population, and should encourage additional research to prevent environmental Cd exposure, both in Brazil and globally.

Blood manganese levels and associated factors in a population-based study in Southern Brazil.

Manganese (Mn) is an essential dietary nutrient for human health serving as a cofactor for many enzymes; however, exposure to excessive quantities of Mn may lead to toxicity with symptoms analogous to Parkinson's disease (PD). Population-based biomonitoring is an effective tool for characterizing the body burden of environmental or occupational pollutants, including Mn. The objective of this cross-sectional study was to (1) estimate reference values (RV) for blood Mn in an adult population and (2) assess the variables that were associated with higher blood metal levels. A total of 947 adults, aged 40 years or older, were randomly selected in a city in Southern Brazil. Information on socioeconomic, dietary, lifestyle, and occupational background was collected by trained interviewers. Blood Mn levels (µg/L) were analyzed by inductively coupled plasma-mass spectrometer (ICP-MS). The RV for blood Mn concentrations were obtained from the upper limits of the 95% confidence intervals (CI) of the 95th percentile distributions. Cluster analysis was performed to identify variables associated with high or low blood Mn concentrations. The RV for blood Mn levels in this study were 18.54 and 20.15 µg/L for men and women, respectively. Mn blood concentrations decreased with age and were higher in females compared to males. No marked association was noted between blood Mn and smoking or drinking habits, education levels and socioeconomic status. Diastolic blood pressure was higher in a group of women approximately 54 years of age associated with elevated blood Mn levels. Important reference data stratified by demographic and lifestyle factors that may prove useful for future surveillance of environmental exposure to Mn and health risks associated with this metal are presented.

Association of lead, cadmium and mercury with paraoxonase 1 activity and malondialdehyde in a general population in Southern Brazil.

Metal exposure is associated with increased oxidative stress (OS), which is considered an underlying mechanism of metal-induced toxicity. Malondialdehyde (MDA) is a final product of lipid peroxidation, and it has been extensively used to evaluate metal-induced OS. Pro-oxidant effects produced by metals can be mitigated by paraoxonase 1 (PON1), an antioxidant enzyme known to prevent cardiovascular disease and atherosclerosis. Among other factors, the Q192R polymorphism and the exposure to heavy metals have been known to alter PON1 activity. Here, we evaluated the association of blood lead (Pb), cadmium (Cd) and mercury (Hg) levels with PON1 activity, and with MDA concentrations in a randomly selected sample of Brazilian adults aged 40 years or older, living in an urban area in Southern Brazil. A total of 889 subjects were evaluated for blood Pb and Cd levels, and 832 were tested for Hg. Geometric mean of blood Pb, Cd and Hg was 1.93µg/dL, 0.06µg/L and 1.40µg/L, respectively. PON1 activity was significantly different among various genotypes: QQ (PON1=121.4U/mL), QR (PON1=87.5U/mL), and RR (PON1=55.2U/mL), p<0.001. PON1 genotypes were associated only with Cd blood levels. Those with QR genotype had Cd concentrations higher (0.07µg/L) than those with the RR genotype (0.04µg/L) with p=0.034. However, PON1 activity was not significantly associated with metal concentrations. Cluster analysis showed that men who reported to be current smokers and drinkers with higher blood Pb and Cd levels, had significantly lower PON1 activity than non-smokers or -drinkers, and women with lower Pb and Cd levels. RR genotype carriers had lower PON1 activity than those with the QR genotype, and had higher levels of Pb and Cd compared with other genotype carriers. For blood Hg, no association with PON1 activity or genotype was noted. We found low levels of Pb, Cd and Hg in environmentally exposed Brazilian adults. Cd concentrations were increased in subjects with QR genotype. Those with RR genotype had lower PON1 activity and higher levels of Pb and Cd than other genotype carriers. The results of cluster analysis suggested that smoking status exerts a significant influence on PON1 activity. Other studies with environmentally exposed populations are required to further clarify whether low blood levels of metals influence OS biomarkers.

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.

Occupational exposure to airborne lead in Brazilian police officers.

Shooting with lead-containing ammunition in indoor firing ranges is a known source of lead exposure in adults. Police officers may be at risk of lead intoxication when regular training shooting exercises are yearly mandatory to law enforcement officers. Effects on health must be documented, even when low-level elemental (inorganic) lead exposure is detected. Forty police officers (nineteen cadets and twenty-one instructors) responded to a questionnaire about health, shooting habits, and potential lead exposure before a training curse. Blood samples were collected and analyzed for blood lead level (BLL) before and after a three days training curse. The mean BLL for the instructors' group was 5.5 µg/dL ± 0.6. The mean BLL for the cadets' group before the training was 3.3 µg/dL ± 0.15 and after the training the main BLL was 18.2 µg/d L± 1.5. Samples were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). All the participants in the training curse had significantly increased BLL (mean increment about 15 µg/dL) after the three days indoor shooting season. In conclusion, occupational lead exposure in indoor firing ranges is a source of lead exposure in Brazilian police officers, and appears to be a health risk, especially when heavy weapons with lead-containing ammunition are used in indoor environments during the firing training seasons.

Lead, hemoglobin, zinc protoporphyrin and ferritin concentrations in children

OBJETIVO: Avaliar a relação entre as concentrações sangüíneas de chumbo, hemoglobina, zinco protoporfirina e ferritina em crianças. MÉTODOS: Estudo transversal realizado com 136 crianças anêmicas e não anêmicas residentes em duas vilas da região rural de Adrianópolis, Estado do Paraná, próximas a uma usina de beneficiamento de chumbo, de julho a setembro de 2001. A eletroforese de hemoglobina foi realizada para excluir as crianças com anemia associada a hemoglobinas variantes e síndromes talassêmicas. O chumbo foi determinado por meio de espectrofotometria de absorção atômica; a hemoglobina por contador celular automático; a zinco protoporfirina por hematofluorometria, e a ferritina por quimioluminescência. Os testes t de student, Mann-Whitney e c2 foram utilizados para verificar a significância das diferenças entre as variáveis. Foi realizada uma análise de regressão linear multivariada stepwise, utilizando dois modelos, para crianças anêmicas e não anêmicas respectivamente. RESULTADOS: No primeiro modelo o chumbo estava negativamente associado com a hemoglobina (p<0,017), e no segundo modelo, estava positivamente associado com a zinco protopofirina (p<0,004), controlando-se por ferritina, idade, sexo e renda per capita. Detectou-se uma associação inversa entre as concentrações sangüíneas de hemoglobina e chumbo, em crianças anêmicas. Não foi possível confirmar se as crianças anêmicas tiveram anemia ferropriva ou infecção subclínica, considerando-se que a maioria delas (90,4 por cento) apresentou concentrações normais de ferritina. CONCLUSÕES: Detectou-se uma relação entre anemia e concentrações sangüíneas elevadas de chumbo. É necessário o desenvolvimento de futuros estudos epidemiológicos investigando o impacto de intervenções nutricionais com ferro na tentativa de diminuição dos níveis sangüíneos de chumbo em crianças.

Lead, hemoglobin, zinc protoporphyrin and ferritin concentrations in children.

OBJECTIVE: To assess the relationship of blood lead and hemoglobin, zinc protoporphyrin, and ferritin concentrations in children. METHODS: A cross-sectional study was carried out in 136 anemic and non-anemic children from two rural villages near a lead smelter in Adrianópolis, Southern Brazil, from July to September 2001. Hemoglobin electrophoresis was performed to exclude children with hemoglobin variants and thalassemia syndromes associated with anemia. Lead was determined by atomic absorption spectrophotometry; hemoglobin by automated cell counting; zinc protoporphyrin by hematofluorometry; ferritin by chemiluminescence. Student's t-test, Mann-Whitney test, and the c(2) test were used to assess the significance of the differences between the variables investigated in anemic and non-anemic children. Stepwise multivariate linear regression analysis was performed using two models for anemic and non-anemic children respectively. RESULTS: Lead was negatively associated to hemoglobin (p<0.017) in the first model, and in the second model lead was positively associated to zinc protoporphyrin (p<0.004) after controlling for ferritin, age, sex, and per capita income. There was an inverse association between hemoglobin and blood lead in anemic children. It was not possible to confirm if anemic children had iron deficiency anemia or subclinical infection, considering that the majority (90.4%) had normal ferritin. CONCLUSIONS: The study detected a relationship between anemia and elevated blood lead concentrations. Further epidemiological studies are necessary to investigate the impact of iron nutritional interventions as an attempt to decrease blood lead in children.

Determinação simultânea de chumbo e cádmio em sangue por / espectrometria de absorção atômica com forno de grafite / Simultaneous determination of lead and cadmium in blood by graphit furnace atomic absorption spectrometry

O sangue é o indicador biológico mais utilizado para avaliar a exposição humana recente ao chumbo e ao cádmio. A espectrometria de absorção atômica com forno de grafite (GFAAS) é uma escolha apropriada para a determinação desses metais em sangue de crianças, em função da capacidade de detectar baixas concentrações e pequeno consumo de amostra. O objetivo deste estudo foi desenvolver e validar uma metodologia para a determinação simultânea de chumbo e cádmio em sangue por GFAAS. O sangue total foi diluído em uma solução de Triton X-100 em HNO3 e uma solução de NH4H2PO4 e Mg(NO3)2 foi utilizadacomo modificador químico. As condições analíticas foram otimizadas e as melhores temperaturas de pirólise e atomização foram respectivamente, 500 °C e 1500 °C. Para validação da metodologia foram utilizados os materiais de referência certificados NIST SRM 955b (Lead in bovine blood) e SRM 966 (Toxic metals in bovine blood). Foram avaliados os seguintes parâmetros para o chumbo e o cádmio, respectivamente: linearidade (5,0 a 100,0 μg.L-1 e 0,3 a 3,0 μg.L-1), exatidão (99,9% e 97,7%), precisão (CV = 3% e 13%), limite de detecção (5,4 μg.L-1 e 0,06 μg.L-1) e limite de quantificação (18,4 μg.L-1 e 2,1 μg.L-1). O método proposto é rápido, sensível e adequado para a determinação simultânea de chumbo e cádmio em sangue detrabalhadores e de populações expostas, incluindo crianças

Descarte de resíduos de laboratório contendo metais pesados (Hg, Pb,Cd) por adsorção em hidróxido de ferro (III) / Disposal of laboratory waste containing heavy metals (Hg, Pb, Cd) by adsorption on iron (III) hydroxide

Para a determinação de metais são freqüentemente utlizadas as soluções-padrão de alta concentração (1000 mg/L) de diferentes íons metálicos. A geração de resíduos contendo esses íons acaba sendo inevitável e um correto gerenciamento desses resíduos é ncessário a fim de se prevenir e reduzir os riscos à saúde humana e ao meio ambiente. No procedimento proposto os íons Hg(II), Pb(II)eCd(II), contidos em soluções ácidas, foram co-precipitados com íons Fe(III) 0,10 mol/L em pH8,5. Após a filtração, o filtrado foi seco ao ar e o sólido foi moído e misturado a uma mistura de cimento/areia(3:1). O procedimento, que consistiu na imobilização dos metais pesados, permitiu que o resíduo pudesse ter um encaminhamento a um aterro de forma segura e eficiente, quanto à preservação da saúde pública e do meio ambiente