New research shows that fish exposed to several different mixtures of a common flame retardant during their early stages of development may experience developmental deformities, behavioral changes and even death.
The research findings were published in the scientific journal Environmental Toxicology and Chemistry, And he is the first to test the effect of this substance on fish.
The flame retardant substance - polybrominated diphenyl ethers (PBDEs) - is found in many common household products, from blankets to sofas to food packaging. Laboratory experiments have shown that this substance is found in breast milk and umbilical cord blood. Previous studies have shown that children whose umbilical cord blood at birth contained high levels of the substance scored lower on tests between the ages of 6 and 2006 years. In XNUMX, the state of California began banning the use of this substance.
This family of substances contains more than two hundred different compounds, which are called subtypes. They are considered low if they contain between 5-1 bromine atoms per molecule.
The researchers, from Baylor University, tested six different compounds from this family for their effects on zebrafish embryos. For 7 days, every day, changes in the behavior, physical deformities and mortality of the fish exposed to these substances were recorded. The findings of the study are:
- Low-bromine compounds were more toxic than high-bromine compounds;
- The fetuses were most sensitive to two specific types of exposures to this substance, the two compounds with the lowest number of bromine atoms, of the six tested. These two compounds caused the curvature of the body's axis, and ultimately the death of the fetus.
- Four of the six compounds tested caused developmental deformities. Five of the six compounds caused changes in behavior, such as reduced swimming abilities and increased spontaneous fetal movement.
"While most of the substances in this family have been banned or completely removed from the market worldwide, it may be more beneficial to identify the specific compounds that are harmful rather than replacing those compounds with chemicals whose biological effects we do not know," said Dr. Erica Bruce, a professor of environmental sciences at Baylor University. . "Changes during early development may result from a disruption in thyroid hormones. These hormones play an essential role in the development of the nervous system and this study provides insights into the biological interrelationships after a few hours of exposure.
