Thyroid hormones play a role in many critical bodily functions, including reproduction and metabolism,BBC reported.

Researchers from Colombia University, US used data from the US National Health and Nutrition Examination Survey to compare thyroid levels and traces of phthalates and BPA in urine samples of 1,346 adults and 329 teenagers.

Their findings confirmed previous research linking BPA used in certain plastic water bottles and the linings of canned foods with disruptions in thyroid hormone levels.

It was found that overall, higher concentrations of the chemicals had an inverse impact on thyroid levels. The greater exposure to phthalates and BPA lower the thyroid hormone levels.

The strongest link occurred with exposure to DEHP, a phthalate commonly used as a plasticizer, which people come into contact through diet.

In the cases of DEHP ingestion, urine samples showed that the greatest exposure was associated with as much as a 10 per cent drop in thyroid hormones.