Household Salt Storage and Seasoning Consumption Are Predictors of Insufficient Iodine Status Among Pregnant Women in Southeastern Brazil.

Iodine deficiency in pregnancy may lead to adverse maternal and fetal outcomes, including impaired child development. Sociodemographic factors and different dietary habits may be related to iodine status in pregnant women. The aim of this study was to evaluate the iodine status and its predictors among pregnant women in a city of Southeastern Brazil. This cross-sectional study was conducted with 266 pregnant women receiving prenatal care in 8 primary health care units. Sociodemographic, obstetric and health, habits of acquisition, storage and consumption of iodized salt, and dietary iodine intake data were collected through a questionnaire. The iodine content was evaluated in urinary iodine concentration (UIC), household salt and seasonings, and drinking water samples. Pregnant women were categorized into three groups according to the UIC, determined by iodine coupled plasma-mass spectrometry (ICP-MS): insufficient (< 150 µg/L), adequate (150-249 µg/L), and more than adequate iodine nutrition (≥ 250 µg/L). The median (p25-p75) UIC was 180.2 µg/L (112.8-262.7). It was found 38% and 27.8% of insufficient and more than adequate iodine nutrition, respectively. Number of gestations, KI content of supplement, alcohol consumption, salt storage, and frequency of using industrialized seasoning were associated to iodine status. Alcohol consumption (OR = 6.59; 95%CI 1.24-34.87), pack the salt in opened container (OR = 0.22; 95%CI 0.08-0.57), and use industrialized seasoning weekly (OR = 3.68; 95% CI 1.12-12.11) were predictors of iodine insufficiency. The pregnant women evaluated have adequate iodine nutrition. Household salt storage and seasoning consumption were risk factors for insufficient iodine status.

Low urinary selenium levels are associated with iodine deficiency in Brazilian schoolchildren and adolescents.

BACKGROUND: Selenium (Se) and iodine (Io) are important micronutrients for the proper functioning of the thyroid gland, as they are crucial for the synthesis and activation of the thyroid hormones (TH) triiodothyronine (T3) and thyroxine (T4). OBJECTIVE: To evaluate the Se and Io nutritional status among schoolchildren. METHODOLOGY: Cross-sectional, descriptive and analytical study conducted in 982 schoolchildren aged 6-14 years from public schools in the state of Bahia, Brazil. Sociodemographic and anthropometric variables, as well as urinary Se (USC) and Io concentrations (UIC) using the inductively coupled plasma mass spectrometry (ICP-MS) method and thyroid-stimulating hormone (TSH) from filter paper blood collection, were evaluated. RESULTS: The median USC and UIC were 38.7 and 210.0 (IQR: 26.8-52.9 and 129.3-334.1 µg/L, respectively). The prevalence of iodine deficiency and excessive UIC were observed in 17.1% and 30.9% of schoolchildren, respectively. Concomitant low USC and IoD was found in 3.9% of schoolchildren. There was a positive correlation between USC and UIC (r = 0.60; p = 0.00). The median TSH was 0.95 (IQR: 0.69-1.30 µUI/L). CONCLUSIONS: This study demonstrates that USC is a good biomarker for assessing Se status, meantime more studies are needed to establish cutoff USC in child population. Despite adequate median intake, a subgroup of schoolchildren had IoD and low USC. The correlation between UIC and USC point at the importance of two micronutrients, raising the question whether measuring Se should be included in monitoring programs that address the prevention of nutritional disturbances.

Association of Salt Iodization and Urine Iodine Concentration in Schoolchildren from Public Schools in Northeast of Brazil.

Iodine deficiency (ID) is recognized as a leading risk factor for child development. Universal salt iodization (USI) is an effective and well-established intervention strategy for the prevention of iodine deficiency disorders (IDD). To evaluate the levels of iodine in household salt samples and the urinary iodine concentration (UIC) in schoolchildren aged 6 to 14 years in public schools in Bahia, Brazil. A cross-sectional study was conducted with 1231 students (6 to 14 years old) from 17 public schools in Bahia. The iodine concentration was evaluated in salt and UIC samples. The adapted Sandell-Kolthoff reaction was used to determine urinary iodine levels. A spectrophotometer (UV-Vis) was used to examine the reduction of ceric ammonium sulfate. A standard iodine solution using a potassium iodate was used to extrapolate the iodine concentrations. The total of 665 salt samples had a median iodine concentration of 24 mg/kg (25th-75th percentile 17.0 to 28.5 mg/kg). The largest proportion (79.6%) of salt samples had iodine concentration in the recommended range, 17.6% of the samples presented iodine at a salt concentration below the established level (<15 mg/kg) and a small proportion was above it (2.8%). The general mean urinary iodine concentration (MUIC) was 217.53 ± 28.30 µg/L and median was 205.50 µg/L. The students evaluated and the salt samples analyzed showed satisfactory results, as recommended by Brazilian legislation and nutritional recommendations of the World Health Organization (WHO).

Edible weeds: Are urban environments fit for foraging?

Foraging wild-growing edible plants (WEPs) is a re-emerging practice with increasing popularity worldwide, including in urban areas. However, in cities, this practice raises questions about the safety of foraging these plants for human consumption, due to the potential exposure of plants to higher levels of pollutants. In this study, the concentration of 12 elements (Al, V, Cr, Mn, Co, Ni, Zn, As, Rb, Cd, Ba and Pb) in three different WEPs (Amaranthus spp., Plantago tomentosa and Taraxacum officinale) were determined according to different traffic categories in the municipality of São Paulo. Additionally, plants were sampled within the inner areas of three municipal parks in the same study region. Different gradients of elemental concentrations were obtained according to the traffic categories. Freeways presented higher concentrations of several elements than local roads or parks. For the WEPs collected along freeways and some plants along arterial roads, the concentrations of Pb exceeded safety levels for human consumption. Our data suggest that foraging in large urban centres should be performed preferentially in low-traffic areas.

Trace element profile in pemphigus foliaceus and in pemphigus vulgaris patients from Southeastern Brazil.

Pemphigus foliaceus (PF) and pemphigus vulgaris (PV) are autoimmune bullous diseases; they are endemic in the northeastern region of the state of São Paulo, Southeastern Brazil. Patients' copper (Cu), zinc (Zn), and selenium (Se) metabolic deficiencies have already been associated with PV pathogenesis in the Middle East but not in Brazil. Lead (Pb), Cu, Zn, and Se concentrations were determined in whole blood or serum samples obtained from 56 PV patients, 62 PF patients, and 135 healthy controls from the endemic region and compared. The PV patients had higher (above the reference values) Pb and lower Zn levels as compared to controls. Both the PV and the PF patients presented decreased Se levels as compared to controls. The PV, PF, and control groups did not differ in terms of Cu concentration. These results indicate that high Pb blood levels are related with environmental contamination and consequently with PV pathogenesis. Moreover, Zn and Se depletion, observed in the PV patients and in the PV and the PF patients, respectively, may result from metabolic consumption verified in chronic diseases.

Using Cluster Analysis and ICP-MS to Identify Groups of Ecstasy Tablets in Sao Paulo State, Brazil.

The variations found in the elemental composition in ecstasy samples result in spectral profiles with useful information for data analysis, and cluster analysis of these profiles can help uncover different categories of the drug. We provide a cluster analysis of ecstasy tablets based on their elemental composition. Twenty-five elements were determined by ICP-MS in tablets apprehended by Sao Paulo's State Police, Brazil. We employ the K-means clustering algorithm along with C4.5 decision tree to help us interpret the clustering results. We found a better number of two clusters within the data, which can refer to the approximated number of sources of the drug which supply the cities of seizures. The C4.5 model was capable of differentiating the ecstasy samples from the two clusters with high prediction accuracy using the leave-one-out cross-validation. The model used only Nd, Ni, and Pb concentration values in the classification of the samples.

The influence of atmospheric particles on the elemental content of vegetables in urban gardens of Sao Paulo, Brazil.

Although urban horticulture provides multiple benefits to society, the extent to which these vegetables are contaminated by the absorption of chemical elements derived from atmospheric deposition is unclear. This study was designed to evaluate the influence of air pollution on leafy vegetables in community gardens of Sao Paulo, Brazil. Vegetable seedlings of Brassica oleracea var. acephala (collard greens) and Spinacia oleracea (spinach) obtained in a non-polluted rural area and growing in vessels containing standard uncontaminated soil were exposed for three consecutive periods of 30, 60 and 90 days in 10 community gardens in Sao Paulo and in one control site. The concentrations of 17 chemical elements (traffic-related elements and those essential to plant biology) were quantified by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Tillandsia usneoides L. specimens were used as air plant biomonitors. The concentrations of As, Cd, Cr and Pb found in vegetables were compared to the recommended values for consumption. Principal Component Analysis (PCA) was used to cluster the elemental concentrations, and Generalized Linear Models (GLMs) were employed to evaluate the association of the factor scores from each PCA component with variables such as local weather, traffic burden and vertical barriers adjacent to the gardens. We found significant differences in the elemental concentrations of the vegetables in the different community gardens. These differences were related to the overall traffic burden, vertical obstacles and local weather. The Pb and Cd concentrations in both vegetables exceeded the limit values for consumption after 60 days of exposure. A strong correlation was observed between the concentration of traffic-related elements in vegetables and in Tillandsia usneoides L. An exposure response was observed between traffic burden and traffic-derived particles absorbed in the vegetables. Traffic-derived air pollution directly influences the absorption of chemical elements in leafy vegetables, and the levels of these elements may exceed the recommended values for consumption.

A brain proteome profile in rats exposed to methylmercury or thimerosal (ethylmercury).

Exposure to organomercurials has been associated with harmful effects on the central nervous system (CNS). However, the mechanisms underlying organomercurial-mediated neurotoxic effects need to be elucidated. Exposure to toxic elements may promote cellular modifications such as alterations in protein synthesis in an attempt to protect tissues and organs from damage. In this context, the use of a "proteomic profile" is an important tool to identify potential early biomarkers or targets indicative of neurotoxicity. The aim of this study was to investigate potential modifications in rat cerebral cell proteome following exposure to methylmercury (MeHg) or ethylmercury (EtHg). For MeHg exposure, animals were administered by gavage daily 140 µg/kg/d of Hg (as MeHg) for 60 d and sacrificed 24 h after the last treatment. For EtHg exposure, 800 µg/kg/d of Hg (as EtHg) was given intramuscularly (im) in a single dose and rats were sacrificed after 4 h. Control groups received saline either by gavage or im. After extraction of proteins from whole brain samples and separation by two-dimensional electrophoresis (2-DE), 26 differentially expressed proteins were identified from exposed animals by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF/TOF). Both MeHg and EtHg exposure induced an overexpression of calbindin, a protein that acts as a neuroprotective agent by (1) adjusting the concentration of Ca(2+) within cells and preventing neurodegenerative diseases and (2) decreasing expression of glutamine synthetase, a crucial protein involved in regulation of glutamate concentration in synaptic cleft. In contrast, expression of superoxide dismutase (SOD), a protein involved in antioxidant defense, was elevated in brain of MeHg-exposed animals. Taken together, our data provide new valuable information on the possible molecular mechanisms associated with MeHg- and EtHg-mediated toxicity in cerebral tissue. These observed protein alterations may be considered as biomarkers candidates for biological monitoring of organomercurial poisoning.

Reference values of cadmium, arsenic and manganese in blood and factors associated with exposure levels among adult population of Rio Branco, Acre, Brazil.

This study aimed to investigate the distribution and factors influencing blood levels of Cadmium (Cd), Arsenic (As), and Manganese (Mn), and to determine their reference values in a sample of blood donors residing in Rio Branco, capital city of Acre State, Brazil. Blood samples were collected from all blood donors attending the Central Hemotherapic Unit in Rio Branco between 2010 and 2011. Among these, 1183 donors (98.9%) answered to a questionnaire on sociodemographic and lifestyle factors. Blood metal concentrations were determined by atomic spectrometry. Association between Cd, As and Mn levels and donors' characteristics was examined by linear regression analysis. Reference values were estimated as the upper limit of the 95% confidence interval of the 95th percentile of metal levels. References values were 0.87 µg L(-1) for Cd, 9.87 µg L(-1) for As, and 29.32 µg L(-1) for Mn. Reference values of Cd and As in smokers were 2.66 and 10.86 µg L(-1), respectively. Factors contributing to increase Cd levels were smoking, ethnicity (non-white), and lower education, whereas drinking tea and non-bottled water were associated with lower Cd. Lower levels of As were associated with higher household income, living near industrial facilities, working in a glass factory, a compost plant or in metal mining activities. Risk factors for Mn exposure were not identified. In general, blood Cd concentrations were in the range of exposure levels reported for other people from the general population, whereas levels of As and Mn were higher than in other non-occupationally exposed populations elsewhere.

Exposure to heavy metals due to pesticide use by vineyard farmers.

OBJECTIVES: To statistically analyze serum heavy metal levels in biological samples obtained from vineyard workers from southern Brazil and check for heavy metal exposure due to pesticide use. METHODS: Serum samples were obtained from 54 farmers and 108 healthy unexposed individuals. Samples from the same farmers were obtained at three different time points over a 1-year period. Levels of lead, arsenic, nickel, zinc, manganese and copper were determined for each sample using dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS). All results were statistically analyzed using the nonparametric Kruskal-Wallis test (followed by Dunn's post hoc test). RESULTS: Results showed that serum heavy metal levels in farmers were twofold to fourfold higher than in controls. This difference was found for all heavy metals tested and was significant (p < 0.05). Serum metal levels among the farmers also correlated with the frequency of use of pesticides at a specific time of year, which varied according to seasonal conditions influencing the need for pesticide application. CONCLUSIONS: It can be concluded that in the vineyard region assessed, farmers were more susceptible to heavy metal exposure due to pesticide use.

A systematic study of the disposition and metabolism of mercury species in mice after exposure to low levels of thimerosal (ethylmercury).

Thimerosal (TM) is an ethylmercury (etHg)-containing preservative used in some vaccines despite very limited knowledge on the kinetics and direct interaction/effects in mammals׳ tissues after exposure. Thus, this study aimed to evaluate the kinetics of Hg species in mice in a time course analysis after intramuscular injection of TM, by estimating Hg half-lives in blood and tissues. Mice were exposed to one single intramuscular dose of 20 µg of Hg as TM. Blood, brain, heart, kidney and liver were collected at 0.5 hour (h), 1 h, 8 h, 16 h, 144 h, 720 h and 1980 h after TM exposure (n=4). Hg species in animal tissues were identified and quantified by speciation analysis via liquid chromatography hyphenated with inductively coupled mass spectrometry (LC-ICP-MS). It was found that the transport of etHg from muscle to tissues and its conversion to inorganic Hg (inoHg) occur rapidly. Moreover, the conversion extent is modulated in part by the partitioning between EtHg in plasma and in whole blood, since etHg is rapidly converted in red cells but not in a plasma compartment. Furthermore, the dealkylation mechanism in red cells appears to be mediated by the Fenton reaction (hydroxyl radical formation). Interestingly, after 0.5 h of TM exposure, the highest levels of both etHg and inoHg were found in kidneys (accounting for more than 70% of the total Hg in the animal body), whereas the brain contributed least to the Hg body burden (accounts for <1.0% of total body Hg). Thirty days after TM exposure, most Hg had been excreted while the liver presented the majority of the remaining Hg. Estimated half-lives (in days) were 8.8 for blood, 10.7 for brain, 7.8 for heart, 7.7 for liver and 45.2 for kidney. Taken together, our findings demonstrated that TM (etHg) kinetics more closely approximates Hg(2+) than methylmercury (meHg) while the kidney must be considered a potential target for etHg toxicity.

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.

Protective properties of quercetin against DNA damage and oxidative stress induced by methylmercury in rats.

Aim of the study was to find out whether consumption of quercetin (QC), an abundant flavonoid in the human diet, protects against DNA damage caused by exposure to organic mercury. Therefore, rats were treated orally with methylmercury (MeHg) and the flavonoid with doses that reflect the human exposure. The animals received MeHg (30 µg/kg/bw/day), QC (0.5-50 mg/kg/bw/day), or combinations of both over 45 days. Subsequently, the glutathione levels (GSH) and the activities of glutathione peroxidase (GPx) and catalase (CAT) were determined, and DNA damage was measured in hepatocytes and peripheral leukocytes in single cell gel electrophoresis assays. MeHg decreased the concentration of GSH and the activity of GPx by 17 and 12%, respectively and caused DNA damage to liver and blood cells, while with QC no such effects were seen. When the flavonoid was given in combination with MeHg, the intermediate and the highest concentrations (5.0 and 50.0 mg/kg/bw/day) were found to cause DNA protection; DNA migration was reduced by 54 and 65% in the hepatocytes and by 27 and 36% in the leukocytes; furthermore, the reduction in GSH and GPx levels caused by MeHg treatment was restored. In summary, our results indicate that consumption of QC-rich foods may protect Hg-exposed humans against the adverse health effects of the metal.

Assessment of trace elements in scalp hair of a young urban population in Brazil.

The aim of this study was to establish background values for toxic and essential elements in hair, interelement correlations and the differences in levels between genders in a healthy young population from Southern Brazil. Hair samples (n=167) were collected from healthy students aged 12-18 years. Trace element concentrations in hair were determined by inductively coupled plasma mass spectrometry. The study provided relatively low values for toxic elements and balanced concentrations for the essential elements in the adolescents' hair with reliable reference data. Interestingly, this study also demonstrated statistical correlations considered newfound between the elements in hair. Hair mercury levels were influenced by gender; with males presenting higher values. The overall findings of the present study, with respect to the estimated chemical elements, are of prime importance in the evaluation of reference values for determining environmental effects on children living in urban areas.