(Reuters Health) - Parents’ exposure to chemicals at work might be linked to eye cancer in their children, a report from some of the world’s leading childhood cancer experts suggests.
The cancer is called retinoblastoma, because it starts in the retina, the back part of the eye. Retinoblastoma accounts for about 6 percent of cancers in children under the age of 5 and about 3 percent of cancers in children under age 15.
“Retinoblastoma is an embryonal tumor, meaning that it arises from tissues of the embryo,” Julia Heck from the Fielding School of Public Health at UCLA told Reuters Health via email. “Six to ten percent of retinoblastoma is ‘familial’ where the child inherits a mutated gene from a parent. The remainder is ‘sporadic’ meaning that these are new mutations that occur in a child’s eye cell, which end up causing the cancer.” The risk of developing “sporadic” retinoblastoma increased substantially when fathers and mothers were exposed to workplace chemicals such as paints, pesticides, and metals, Heck and her colleagues found.
The research team studied 282 children with sporadic retinoblastoma, plus 155 of the children’s healthy friends, as well as all the parents.
Fathers were asked to report all jobs held in the ten years prior to conception. Mothers reported jobs held the month prior to conception in addition to any jobs they had while pregnant. The researchers then assigned an overall “exposure” score to each job with regards to nine hazardous agents.
Results showed that children of fathers who were exposed to workplace paint in the past ten years were more than eight times more likely to have retinoblastoma than children whose fathers were not exposed. Fathers who were at least 30 years old when they were exposed to at least one of the nine agents had a nearly seven times higher risk of having a child diagnosed with retinoblastoma.
Mothers’ exposure to at least one of the nine hazardous agents in the month prior to conception or during pregnancy was associated with more than five times higher odds that their child would have retinoblastoma.
The research was done by the Children’s Oncology Group, a National Cancer Institute-backed coalition devoted exclusively to researching and understanding cancers in youngsters. The entire report can be found online in Occupational and Environmental Medicine.
Exposure to chemical agents including welding fumes, sulfur dioxides, and polycyclic aromatic hydrocarbons is rampant among workers in agriculture, coal mining, and aluminum reduction. These agents have previously been associated with an increased risk of childhood brain cancers and leukemia.
Although the most common eye cancer in children, retinoblastoma is very rare, with just one in every 200,000 births.
“Only 200 to 300 children are diagnosed each year in the U.S.,” Greta Bunin from Children’s Hospital of Philadelphia, who worked on the study, told Reuters by email.
Nonetheless, couples actively trying to conceive should be aware of the potential connection and, if possible, ask for a temporary reassignment from employers to avoid further exposure, at least in the short-term.
What measures should be taken from an occupational or environmental policy standpoint to lessen the risks? From a policy perspective, prevention might not be so easy.
“Of course this cancer is rare and some may argue that it is hard to make broad policies to impact the incidence of such a rare disease,” Heck acknowledged. “I would say that our study contributes to the literature examining the health risks in workers and their offspring from occupational chemical exposures and provides another reason to suggest that protections are taken.”