Parents, take note! Infants who eat rice and rice products - typical first foods for babies - may have higher urinary arsenic concentrations than those who do not, a new US study has warned.

Arsenic exposure from rice is a concern for infants and children, researchers said. Previous research suggests that arsenic exposure in utero - and early in life - may be associated with adverse effects on foetal growth and child immune and neurodevelopment outcomes.

Infant rice cereal may contain inorganic arsenic concentrations that exceed the recommendation from the World Health Organisation (WHO) of 200 nanogram/gram (ng/g) for polished white rice and the new European Union regulations of 100 ng/g for products aimed at infants.

Researchers from Dartmouth College in the US examined the frequency with which infants ate rice and rice-containing products in their first year of life, as well as the association with arsenic concentrations in the urine.

The study included 759 infants born to mothers in the New Hampshire Birth Cohort Study from 2011 to 2014. The infants were followed up with phone interviews every four months until 12 months of age.

At 12 months, dietary patterns during the past week were assessed, including whether the infant had eaten rice cereal, white or brown rice or foods either made with rice - such as rice-based snacks - or sweetened with brown rice syrup - such as some brands of cereal bars.

Infant urine samples were collected beginning in 2013 along with a 3-day food diary.

Researchers found that 80 per cent of the 759 infants were introduced to rice cereal in the first year of life with most (64 per cent) starting at 4 to 6 months of age. At 12 months, 43 per cent reported eating some type of rice product in the past week; 13 per cent are white rice and 10 per cent ate brown rice at an average of one to two servings per week.

About 24 per cent of infants ate food made with rice or sweetened rice syrup in the past week at an average of five to six servings per week. Based on information recorded in food diaries two days before urine sample collection, 71 infants (55 per cent) consumed some type of rice product in the prior two days.

Results indicated that arsenic concentrations were higher among infants who ate rice - or foods mixed with rice - compared with infants who ate no rice. Also, total urinary arsenic concentrations were twice as high among infants who ate white or brown rice compared with those who ate no rice.

The highest urinary arsenic concentrations were seen among infants who ate baby rice cereal. It was nearly double for those who ate rice snacks compared with those who ate no rice.