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

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.

Chemical monitoring of river water bodies in an EU outermost region: examples from the Azores archipelago (Portugal).

Chemical monitoring of water quality on a total of 16 rivers in the Azores archipelago (Portugal), since 2003, made it possible to identify the major pressures and spatial geochemical variations along main course of the rivers. River water pollution is to a large extent associated to point sources, namely domestic wastewater discharges, especially in urban areas, and diffuse sources, associated with pasture land, and explain the high values on BOD(5) and nutrients (P and N). Heavy metals and metalloids, as well as hydrocarbons and pesticides, are generally under the detection limits of the analytical methods. Generally, river water reflects pollution loads according to a simple model, derived from land use in the watershed: in the upper part conditions are pristine, in the intermediate portion of the basin pasture land dominates and near the coast urban discharges are increasingly important. Results stress the role that an approach based on the watershed scale, coupled with land use management measures, are crucial to water management procedures and a successful WFD implementation in small river basin districts like the Azores. The paper also shows the need for full compliance regarding EU directives on urban wastewater and nitrate pollution due to agriculture.