|
Scientists have claimed that women exposed to high levels of certain banned environmental pollutants give birth to fewer baby boys.
According to a study published in Environmental Health, women exposed to higher levels of PCBs (polychlorinated biphenyls) are 33 percent less likely to give birth to boys.
More specifically, the chance of having a boy falls by seven percent
for every one microgram per liter increase in PCBs serum levels during
pregnancy.
Scientists believe that high levels of PCBs put embryos at a greater risk of loss and favor fertilization by XX chromosomes sperms.
Chemicals such as flame-retardants (polybrominated diphenyl ethers)
currently used in plastic casings and foam products, have similar
biochemical and toxicological properties to PCBs.
PCBs are organic pollutants, which were widely used in products such as varnishes and caulks and in cooling and insulating
fluids for electrical equipment. They were banned in 1970 due to their
harmful effects on the human immune, reproductive, nervous, and endocrine systems.
Exposed/p.t of Expose/:
reveal, uncover, disclose; abandon
Fertilization/n./:
impregnation, insemination
Toxicological/adj./:
of or related to the study of poisons وابسته به زهرشناسى
Insulating/adj./:
of
insulate, seal or close off with a material which blocks or retards the
passage of heat (or electricity, sound, etc.); isolate
endocrine/n./:
internal hormonal secretion
|
