To Örebro University

Background: Since we spend most of our time indoors the indoor environment can lead to exposure to substances like metals. Small children are often more exposed than adults, for instance due to their hand-to-mouth behaviour. Since some metals can have adverse health effects in children the aim of this study was to investigate indoor exposure to metals on children’s hands in preschools.

Method: In the study, 60 children at 8 preschools in two cities in Sweden participated. Metals on the hands were sampled at two different periods (winter and spring) giving a total of 109 samples. During sampling, both hands were wiped using hand-wipes soaked in 1 % HNO3, and sampling was done after two hours of indoor activities. The following metals were analyzed using ICP-MS; beryllium, magnesium, aluminium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, molybdenum, silver, cadmium, antimony, barium, thallium and lead. Results All samples were above limit of quantification (LOQ) except for beryllium and molybdenum (4 %<LOQ) and silver (100 %<LOQ, LOQ=0.001 µg/sample). The lowest mean level was seen for beryllium (0.0034 µg/sample) and highest for magnesium (140 µg/sample). For cadmium, arsenic and lead the mean levels were 0.023, 0.049 and 0.51 µg/sample, respectively. For about half of the metals statistically significantly higher levels (p<0.05) were seen during spring and in one of the cities.

Conclusion: Metals linked to severe health effects like cadmium, arsenic and lead as well as a range of other metals could be detected on children’s hands. These findings indicate an exposure to metals for children both via dermal uptake and oral intake due to hand-to-mouth transfer, but potential contributions to the body burden are unknown. Higher levels were seen during spring and in one of the cities, possible explanations to these observations needs to be looked into more closely.