Experts have said people should not be alarmed by research claiming a link between pesticides in food and cancer.
The researchers suggest chemicals can be passed to babies in breast milk
A team from Liverpool University reviewed studies carried out in the lab and on animals.
The Journal of Nutritional and Environmental Medicine study said it was feasible babies and young adults were at risk from the chemicals.
But Professor John Toy of Cancer Research UK said the work did not offer "compelling" evidence of a link.
The review looked at over 300 studies published on the effects of organochlorines, contained in pesticides and some plastics, which may be passed to humans by drinking water, eating meat and dairy products or being breathed in.
They are believed to affect hormone production, raising concerns about links to hormone-related cancers such as breast, prostate and testicular
The researchers say their examinations suggest that, even if healthy adults are not at risk from the low-level concentrations of the chemicals, babies in the womb and those who are being breastfed might be.
They suggest the chemicals can be transferred from a mother to baby via breast milk.
It is also feasible the risks for children and young adults have been underestimated, they say.
Professor Vyvyan Howard, one of the authors of the research who is on the government's pesticides advisory committee, said: "For humans the main source of organochlorine exposure is from diet, primarily through meat and dairy products.
"Children are exposed to dioxin, a by-product of organochlorines, through food.
"Breastfed infants can be exposed to organochlorines that have accumulated in breast milk."
He added: "Preventative measures for these types of cancer have focused on educating the public about the danger of tobacco smoke, improving diet and promoting physical activity.
"We should now, however, be focusing on trying to reduce exposure to problematic chemicals."
Jamie Page, Chairman of the Cancer Prevention and Education Society, which campaigns to reduce exposure to potentially cancer-causing chemicals, said: "This research is very important and suggests that there are links between chemicals and cancer."
But Professor John Toy, Cancer Research UK medical director, said: "People should not be alarmed by this study.
"It is a review of previously reported research and does not present new findings.
"The authors suggest that it is feasible that certain chemicals could be a factor in causing cancer but do not find compelling scientific evidence to prove a link."
Rosie Dodds, of the National Childbirth Trust said: "While there is reason for parents to be concerned about the level of chemicals their baby is exposed to, it is wrong to suggest that women who are breastfeeding, or who plan to breastfeed, should be more concerned, or indeed refrain from breastfeeding their baby, because of worry about levels of chemicals and pesticides in breastmilk."