Exposure to Selected Geogenic Trace Elements (I, Li, and Sr) from Drinking Water in Denmark

Abstract

The naturally occurring geogenic elements iodine (I), lithium (Li), and strontium (Sr) have a beneficial effect on human health. Iodine has an essential role in human metabolism while Li and Sr are used, respectively, as a treatment for various mental disorders and for post-menopausal osteoporosis. The aim here is to evaluate the potential for future epidemiological investigations in Denmark of lifelong and chronic exposure to low doses of these compounds. The drinking water data represents approximately 45% of the annual Danish groundwater abstraction for drinking water purposes, which supplies approximately 2.5 million persons. The spatial patterns were studied using inverse distance weighted interpolation and cluster analysis. The exposed population was estimated based OPEN ACCESSGeosciences 2015, 5 46 on two datasets: (1) population density in the smallest census unit, the parishes, and (2) geocoded addresses where at least one person is residing. We found significant spatial variation in the exposure for all three elements, related mainly to geochemical processes. This suggests a prospective opportunity for future epidemiological investigation of long-term effects of I, Li, and Sr, either alone or in combinations with other geogenic elements such as Ca, Mg or F.

Nationwide Drinking Water Sampling Campaign for Exposure Assessments in Denmark

“…the digital geocoded data collected in this study). This map enables the spatial connection between water quality supplied by the Danish waterworks with the resident history, health, and economic-social status on a personal level for the entire Danish population (see example in [ 2 ]).…”

“…Iodine is essential element that plays important role in the metabolism and early development of humans, but there was limited information on the local and regional variability of iodine species in Danish drinking water prior to our study [ 1 ]. Even though the main focus was on iodine, the resulting dataset can be used further for drinking water exposure assessments on other elements (e.g., lithium and strontium [ 2 ]) and following epidemiological studies (e.g., [ 3 , 4 , 5 ]). The methodology was briefly described in [ 1 , 2 ] with a focus on only few of the used analytes.…”

“…Even though the main focus was on iodine, the resulting dataset can be used further for drinking water exposure assessments on other elements (e.g., lithium and strontium [ 2 ]) and following epidemiological studies (e.g., [ 3 , 4 , 5 ]). The methodology was briefly described in [ 1 , 2 ] with a focus on only few of the used analytes. In contrast, this technical note provides information on the entire dataset (major part of which has not been reported yet in peer-review publications).…”

“…Therefore, in this technical note, we first provide some background on Danish drinking water supply to set the scene, and then we elaborate on the design and implementation of this drinking water sampling campaign. The dataset resulting from our drinking water campaign has so far been used in several studies [ 1 , 2 , 3 , 4 , 5 ] (status March 2017). We foresee that the details provided in this technical note will facilitate the future use of this “historical” dataset and will inform potential replication studies in Denmark.…”

Iodine in major Danish aquifers

“…In general, water has been seen as a minor or even negligible iodine source (Fuge 2005). However, local or regional geographical variation can exist and be important for the iodine intake of the population in areas where drinking water is of groundwater origin, as in Denmark (Pedersen et al 1999;Laurberg et al 2006;Voutchkova et al 2014aVoutchkova et al , 2015 or as in China (Shen et al 2011;Lv et al 2013). Iodine speciation and concentrations in drinking water and groundwater in Denmark have not been studied extensively.…”