Whilst their intake of heavy metals from food sources is lower than it was for their parents at the same age, many young Finnish children’s exposure to cadmium, lead and arsenic still exceeds the latest safety levels set by the EU, the study found.
This risk assessment study was requested after several assessments carried out by the European Food Safety Authority (EFSA) showed that heavy metal exposure among Finnish children was above acceptable levels for a significant part of the population.
Sources and causes
Heavy metals accumulate in food from natural sources in the environment as well as from emissions caused by human activities, such as the mining of non-iron ores, industry emissions, and the use and preparation of phosphate fertilisers.
The current study found that grains and potatoes are the most significant source of cadmium for children, whilst the main source of inorganic arsenic is rice-based foods.
Looking at data for one-year old, three year-old and six year-old children living in the Pirkanmaa area of Finland, they found that exposure to cadmium from food and tap water exceeded the tolerable weekly intake (2.5 per kilo body weight per week) for a large proportion of the studied children.
“Even though the exposure decreases as a child grows, steps to reduce the exposure to cadmium at the population level would be beneficial,” wrote the researchers.
Although exposure to lead in Finland has declined considerably in recent years owing primarily to the shift to unleaded petrol, a large percentage of the child population was still found to exceed the benchmark dose lower confidence limit (BMDL) of 0.5 μg per kilo body weight per day, determined in 2010.
For arsenic, according to lower estimates, 10–29% of the studied children exceeded EFSA's limit of 0.3 per kilo body weight per day. This range was much higher for mid estimates (29–79%). Even then, the BMDL determined by FAO and WHO of 3 μg/kg bw/day was not exceeded.
“Exceeding the BMDL means that if the exposure exceeds this level on every day of a person’s life, the lifetime cancer risk will be increased by 1%,” said the researchers.
Improvement on EFSA results
These exposure levels were lower than those estimated by EFSA in their risk assessments, for reasons explained by Prof. Suomi: “The data assessed by EFSA are mainly from Central European member states, and the average concentrations in some foods and raw agricultural commodities in Finland were different from the average concentrations quoted in the EFSA reports.
“In particular, the average levels of lead in tap water and cereals were found to be lower in Finland than the EU average. This is why, in the current national study, where we used concentration data from foods either produced in Finland or imported to Finland, exposure levels were found to be lower.”
Preventative and legislative measures
In the EU, legislation sets maximum limits for heavy metals in food and drinks, whilst tap water is nationally regulated. The maximum levels have been tightened recently and new limits added, for example, for arsenic in rice. Fertilisers are also controlled for their heavy metal content.
Prof. Suomi said that the legislative changes and resulting stricter control by authorities and industry had already helped to reduce the occurence of heavy metals in the food chain.
“We hope the current good trends can be continued to decrease levels further. Our aim in Finland is to continue the current good practices in agriculture and industry as well as to protect the population through risk communication.”
The food safety authority hasn’t issued any new advice in the light of these findings, but has emphasised the importance of ensuring children have a varied diet.