Using cattle hair to assess exposure to essential trace elements in volcanic soils.

BACKGROUND: In areas where cattle graze outdoors, the environmental availability of trace elements is of utmost importance for an adequate intake. Cattle hair trace elements can be used as exposure biomarkers to assess animal intake and help ensure good nutrition and animal welfare. The aim of this study was to evaluate the environmental exposure to trace elements in cattle grazing outdoors in a volcanic region (São Miguel Island, Azores) and assess the corresponding bioaccumulation factors. METHODS: Twenty-nine samples of pasture topsoil were collected in two areas of São Miguel with different geological characteristics: Picos fissure system (basaltic area) and Povoação volcano (trachytic area). Hair from fifty-four animals (calves and dairy cows) was collected in two grazing sites: Ponta Delgada (Picos fissure system) and Povoação (Povoação volcano). All samples were analysed by inductively coupled plasma mass spectrometry (ICP-MS) after digestion in aqua regia. RESULTS: Basaltic soils of the Picos fissure system had significantly higher concentrations of most trace elements, except Mo, when compared with the trachytic soils of Povoação volcano. Hair of calves from Povoação showed higher concentrations of most essential trace elements, except Mg, Cu, and Zn, than hair from calves of Ponta Delgada (considered in this study as a control group since they are raised in a barn). On the other hand, hair from dairy cows grazing in Ponta Delgada showed higher concentrations of most essential trace elements, except Mg, As, and Mo, when compared with hair of cows grazing in Povoação. CONCLUSIONS: Cattle hair trace elements are suitable biomarkers for the assessment of the environmental exposure to trace elements in volcanic soils. The results from dairy cows support the uneven distribution of essential trace elements (and their bioavailability) in the different soils of São Miguel, reinforcing the need to graze animals outdoors from an early age. Such practice (grazing cattle outdoors) provides another means of accessing essential trace elements that complemented with feed can reduce the natural depletion of these essential elements in the body due to reproductive phenomena and milk production.

Iodine Intake and Related Cognitive Function Impairments in Elementary Schoolchildren.

Iodine deficiency, the most common cause of preventable mental impairment worldwide, has been linked to poorer intellectual function in several studies. However, to our knowledge, no studies have been performed in moderate iodine-deficient schoolchildren using the complete form of Wechsler Intelligence Scale for Children (WISC-III; Portuguese version). The main purpose of this study was to ascertain whether moderate iodine deficiency would affect the cognitive function of schoolchildren (7-11 years old; 3rd and 4th grades). Raven's Colored Progressive Matrices (CPM; Portuguese version) were used for measuring the intelligence quotient (IQ) of the total population (n = 256; median UIC = 66.2 µg/L), and the WISC-III was used to study two selected subgroups: one moderately iodine-deficient (n = 30) and the other with adequate iodine intake (n = 30). WISC-III was shown to be the prime instrument for cognitive function assessment among moderate iodine-deficient schoolchildren; this subgroup had a Full-Scale IQ 15.13 points lower than the adequate iodine intake subgroup, with a magnitude effect of d = 0.7 (p = 0.013). Significant differences were also registered in 6 of the 13 Verbal-Performance IQ subtests. Moderate iodine deficiency has a substantial impact on mental development and cognitive functioning of schoolchildren, with significant impairment in both Performance IQ and Verbal IQ spectrum, adversely impacting their educational performance.

Deficiency of essential elements in volcanic soils: potential harmful health effects on grazing cattle.

Several essential nutrients such as Fe, Co, Cu, I, Se, and Zn are vital to grazing cattle as they play a significant role in intracellular enzyme systems, with antioxidant and repair functions of DNA lesions. Feeds may supply most essential nutrients in adequate amounts. However, essential nutrient deficiencies are common and are mainly related to the geochemical characteristics of the soils, inherited from parent rocks. This study aims to assess the concentrations of the selected essential nutrients in topsoils and pasture grass from São Miguel Island (Azores) and discuss the possible effects of its deficiency in grazing cattle health. Sixty-eight samples of agricultural (pastures) topsoil and thirty samples of pasture grass were collected throughout São Miguel Island in areas with basaltic and trachytic parent rocks. Soil physicochemical properties and geochemical baselines of selected elements were determined on composite samples of soil and pasture grass in each site. Results indicate that the highest concentrations of the selected essential nutrients were observed in areas with basaltic soils, while the lowest values were found in areas with trachytic soils. These differences are considered of geogenic origin since they result from the weathering of volcanic parent rocks with different geochemical compositions. Data indicate a lack of some essential nutrients in topsoils (Co and Se) and/or pasture grass (Co, Cu, Se, and Zn) that can contribute to harmful health effects on grazing cattle. The uneven distribution of essential nutrients in topsoil and pasture grass and their deficiency can lead to several health problems in the cattle since these elements regulate physiological functions in biological systems. The identification of these deficit sites is important as it can help farmers to implement soil and/or animal supplementation programs to diminish possible health problems.

Cobalt distribution in the soils of São Miguel Island (Azores): From volcanoes to health effects.

Volcanic soils cover only approximately 1% of the Earth's surface, yet they support 10% of the world's population due to their inherent fertility. However, deep magmatic processes may lead to depletion of certain elements in volcanic rocks. The imbalance of essential elements, such as cobalt, in soil parent materials can affect the health of plants and grazing animals and, thus, humans. Within the particular geological context of the Azores, the present study aims to assess cobalt concentration in volcanic soils to predict the risk of cobalt deficiency in animals and humans. Samples from agricultural topsoils and pasture grass were collected in six volcanic regions of São Miguel Island, and their physicochemical properties were measured, including selected transition metal element contents, such as iron, manganese and cobalt. The soil cobalt concentration was below 5 mg/kg in Povoação< Furnas/Congro< Sete Cidades< Fogo and was higher than 10 mg/kg in Picos< Nordeste. Cobalt concentrations were very low in pasture grass. Values below 0.1 mg/kg were observed in Furnas/Congro

Buccal epithelial cell micronuclei: Sensitive, non-invasive biomarkers of occupational exposure to low doses of ionizing radiation.

We have evaluated buccal epithelial cell micronucleus formation as a biomarker of genotoxic damage following occupational exposure to low doses of ionizing radiation. Buccal epithelial cells were collected from 42 occupationally exposed medical personnel and 39 non-exposed individuals (reference group). Each individual in the exposed group was routinely monitored with a personal radiation badge. The frequency of micronucleated cells (MNC) was significantly higher in the exposed group (5.26 vs. 1.33 MNC/2000 cells) and correlated strongly with accumulated radiation dose (Annual Deep Dose, mSv). Occupational exposure to low doses of ionizing radiation was associated with an 80% relative increase in the frequency of MNC (MRR = 1.8; 95% CI: 1.1-2.8), suggesting that such exposures cause DNA damage. This non-invasive biomonitoring method should be generally applicable to studies of workers who are exposed occupationally to low doses of IR.

Mus musculus bone fluoride concentration as a useful biomarker for risk assessment of skeletal fluorosis in volcanic areas.

Fluoride is often found in elevated concentrations in volcanic areas due to the release of magmatic fluorine as hydrogen fluorine through volcanic degassing. The exposure to high levels of fluoride can affect the processes of bone formation and resorption causing skeletal fluorosis, a pathology that can easily be mistaken for other skeletal diseases. In this study, we aimed to determine if fluoride concentration in the femoral bone of wild populations of the house mouse (Mus musculus) is a good biomarker of exposure to active volcanic environments naturally enriched in fluoride, allowing their use in biomonitoring programs. The fluoride concentration of the whole femoral bone of 9 mice from Furnas (5 males and 4 females) and 33 mice from Rabo de Peixe (16 males and 17 females) was measured by the potentiometric method with a fluoride ion selective electrode. Fluoride in bones was significantly higher in the mice from Furnas when compared with the mice from Rabo de Peixe (616.5 ±â€¯129.3 µg F/g vs. 253.8 ±â€¯10.5 µg F/g). Accumulation rates were also significantly higher in the mice collected in Furnas when compared with Rabo de Peixe individuals (3.84 ±â€¯0.52 µg F/day vs. 1.22 ±â€¯0.06 µg F/day). The results demonstrate a significant association between exposure to fluoride in the active volcanic environment and fluoride content in bone, revealing that bone fluoride concentration is a suitable biomarker of chronic environmental exposure to fluoride.

DNA damage in oral epithelial cells of individuals chronically exposed to indoor radon (222Rn) in a hydrothermal area.

Hydrothermal areas are potentially hazardous to humans as volcanic gases such as radon (222Rn) are continuously released from soil diffuse degassing. Exposure to radon is estimated to be the second leading cause of lung cancer, but little is known about radon health-associated risks in hydrothermal regions. This cross-sectional study was designed to evaluate the DNA damage in the buccal epithelial cells of individuals chronically exposed to indoor radon in a volcanic area (Furnas volcano, Azores, Portugal) with a hydrothermal system. Buccal epithelial cells were collected from 33 individuals inhabiting the hydrothermal area (Ribeira Quente village) and from 49 individuals inhabiting a non-hydrothermal area (Ponta Delgada city). Indoor radon was measured with Ramon 2.2 detectors. Chromosome damage was measured by micronucleus cytome assay, and RAPD-PCR was used as a complementary tool to evaluate DNA damage, using three 10-mer primers (D11, F1 and F12). Indoor radon concentration correlated positively with the frequency of micronucleated cells (r s = 0.325, p = 0.003). Exposure to radon is a risk factor for the occurrence micronucleated cells in the inhabitants of the hydrothermal area (RR = 1.71; 95% CI, 1.2-2.4; p = 0.003). One RAPD-PCR primer (F12) produced differences in the banding pattern, a fact that can indicate its potential for detecting radon-induced specific genomic alterations. The observed association between chronic exposure to indoor radon and the occurrence of chromosome damage in human oral epithelial cells evidences the usefulness of biological surveillance to assess mutations involved in pre-carcinogenesis in hydrothermal areas, reinforcing the need for further studies with human populations living in these areas.

Safety Evaluation of Fluoride Content in Tea Infusions Consumed in the Azores-a Volcanic Region with Water Springs naturally Enriched in Fluoride.

Tea is the second most commonly consumed beverage in the world. It is well recognized that the consumption of tea in high quantities can promote the development of fluorosis. The main objective of this study is to estimate the exposure to fluoride in the Azores through drinking tea prepared with water from different volcanic locations, by i) investigating the fluoride (F) content of various commercial brands of tea (Camellia sinensis) marketed in Azores and ii) comparing tea releasing rates of F according to brewing time, considering the fluoride concentration in the different types of water used for the infusion. Fluoride contents were determined by ion-selective electrode in 30 samples of drinking water from three different locations and in 450 samples of tea (black and green tea) from three different brands. Fluoride concentration in water ranged from 0.29 to 1.56 ppm (Porto Formoso and Sete Cidades village, respectively). Fluoride concentrations increased with brewing time, reaching the highest values in the Azorean black and green tea infusions. For all the studied brands, a negative correlation was found between tea fluoride contents and the pH of the water used to prepare the infusion. Fluoride concentration in infusions was significantly associated with the background fluoride concentration in drinking water. Since the fluoride concentration in groundwater varies accordingly to the geological conditions and tea consumption can contribute to fluoride intake, it is important to define the limits for tea consumption, particularly in fluoride-rich areas. Graphical Abstract Fluoride concentrations in black and green tea for 3 minutes of brewing time and, association between fluoride concentration and pH with brewing time.

Sensitivity of two biomarkers for biomonitoring exposure to fluoride in children and women: A study in a volcanic area.

The natural enrichment of water with fluoride is related to natural sources such as volcanic activity, with it being documented that fluorosis, an endemic and widespread disease in volcanic areas, is associated to the ingestion of high levels of fluoride through water. Thus, in this study, we aimed to define the fluoride concentration in drinking waters of volcanic origin and compare the sensitivity of urine and nail clippings as biomarkers for fluoride exposure in adults and children. Samples of drinking water from four villages in São Miguel Island (Azores) were used and the fluoride concentration was determined, as well the fluoride content in urine and toenails clippings from 66 children and 63 adults from these villages. A validated diet questionnaire, assessing sources of fluoride, was recorded for each participant. The fluoride determination in urine and nail clipping samples was made using a fluoride-specific electrode. A positive correlation was found between the fluoride daily intake and fluoride content in children urine (rs = 0.475; p < 0.001) and in their nail clippings (rs = 0.475; p < 0.001), while in adult women, the fluoride daily intake correlated positively with fluoride content nail clippings (rs = 0.495, p < 0.001). This reveals that nail clippings are more reliable as biomarkers of chronic exposure to fluoride than urine for populations of different ages (children vs. adults). Furthermore, nail clippings are more suitable than urine fluoride levels to assess long term exposure to fluoride in areas where the exposure to fluoride in drinking water is considered within, or slightly above, the recommended legal values.

Air Pollution by Hydrothermal Volcanism and Human Pulmonary Function.

The aim of this study was to assess whether chronic exposure to volcanogenic air pollution by hydrothermal soil diffuse degassing is associated with respiratory defects in humans. This study was carried in the archipelago of the Azores, an area with active volcanism located in the Atlantic Ocean where Eurasian, African, and American lithospheric plates meet. A cross-sectional study was performed on a study group of 146 individuals inhabiting an area where volcanic activity is marked by active fumarolic fields and soil degassing (hydrothermal area) and a reference group of 359 individuals inhabiting an area without these secondary manifestations of volcanism (nonhydrothermal area). Odds ratio (OR) and 95% confidence intervals (CIs) were adjusted for age, gender, fatigue, asthma, and smoking. The OR for restrictive defects and for exacerbation of obstructive defects (COPD) in the hydrothermal area was 4.4 (95% CI 1.78-10.69) and 3.2 (95% CI 1.82-5.58), respectively. Increased prevalence of restrictions and all COPD severity ranks (mild, moderate, and severe) was observed in the population from the hydrothermal area. These findings may assist health officials in advising and keeping up with these populations to prevent and minimize the risk of respiratory diseases.

Iodine environmental availability and human intake in oceanic islands: Azores as a case-study.

Iodine deficiency is the most common cause of preventable mental impairment. Although several studies have established an association between ocean proximity and iodine environmental availability, recent studies revealed an inadequate iodine intake in the Azorean islands. In this study, we aim to understand the underlying causes of iodine environmental availability in oceanic islands and its association with iodine intake in schoolchildren, using the Azores as case-study. Iodine concentration in soil and grass pasture was measured by INAA and in drinking water by spectrophotometry. Urinary iodine concentration (UIC) in schoolchildren was assessed by ICP-MS in a randomized cross-sectional survey with 315 participants from S. Miguel (study group) and Sta. Maria islands (reference group). A validated diet questionnaire assessing sources of iodine was recorded. The iodine concentration in soils of the reference group was significantly higher than in the study group (58.1ppm vs. 14.5ppm, respectively; p=0.001). The prevalence of schoolchildren with inadequate UIC was significantly higher in the study group than in the reference one (63.0% vs. 37.8%, respectively; p<0.001). Chronic exposure to low iodine environmental availability was significantly associated with the exacerbation in iodine deficiency, with a risk 4.94 times higher in the study group. The differences observed in the studied islands are related with each island geomorphology (soil properties and orography) and climate, which can promote or inhibit iodine environmental availability, contributing distinctively to iodine bioavailability and human intake. These findings draw attention to an urgent need for a full investigation of Azores iodine status to apply evidence-based recommendations for iodine supplementation.