According to a new study, breastfeeding may expose todlers to a widely used class of industrial chemicals. The toxins can lead to developing cancer and interfer with immune function.

Perfluorinated alkylate substances (PFASs) are a class of widely used industrial chemicals. According to new research, they appears to build up in infants by 20 to 30% for each month of breastfeeding. The study was conducted by experts from Harvard TH Chan School of Public Health.

According to scientists, this research is the first to show the extent to which PFASs can transfer to babies through breast milk. The research team explains that they knew that small amounts of PFAS can occur in breast milk, but their new study involved serial blood analyses that show now a buildup in the infants.

The levels of toxic chemicals buildup get higher the longer the babies are breastfed, according to the adjunct professor of environmental health at Harvard Chan School, Philippe Grandjean. The professor explained that PFASs are used to make products resistant to stains, grease and water.

PFASs compounds have been used in different industrial applications for more than 60 years including products such as waterproof clothing, stain-proof textiles, lubricants, paints and some food packaging. Scientists already knew that these chemicals contaminate drinking water in the US near various production facilities.

These compounds can besist for a long time in the body as they tend to bioaccumulate in food chains. They have been linked with endocrine disruption, reproductive toxicity, and immune system suppresion. Unfortunately, they are found regularly in the blood of humans and animals worldwide.

The results of the new study suggest that breast milk is a major source of PFAS exposure during infancy, according to researchers. This conclusion should not discourage breastfeeding, the scientists said, however they are concerned that these pollutants can transfer to the next generation at a very vulnerable age.