The Birds and The PCBs talks about....Birds and PCBs

When I started this blog, I didn't think I was going to literally be blogging about birds and PCBs. But apparently I wrong.

I now present you with a heartbreaking story of songbirds, toxic chemicals, and tainted love. Sigh.

Researchers have found that chickadees that are exposed to very small, allowable levels of polychlorinated biphenyls (PCBs) can’t keep a tune as well as other birds. Like many bird species, in chickadees, the females go for males with the best songs. So, PCB-exposed birds might lose out on mates, says Sara DeLeon, an ecologist at Cornell University.

The Cornell scientists examined chickadees living along New York’s Hudson River, not far from a General Electric power plant that used PCB insulators from 1907 until the 1970s, dumping some 500,000 kilograms of the toxic chemical into the river. The US government ordered GE to clean the PCB-contaminated waters, one of the country’s largest waste cleanups. Even though current levels are below EPA's regulatory limits and thus deemed "safe," traces remain in many sites on the river, and are impacting wildlife in subtle ways

PCBs, or polychlorinated biphenyls, are a class of yucky chemicals that were banned in the 1970s for being persistent organic pollutants (POPs). They are found to bioaccumulate in people and animals. They also have subtle effects in human, such as influencing sex ratios.

While the lackluster love songs of the PCB-contaminated birds could be a warning to the female chickadees that their mates aren't healthy, this could pose some serious problems for bird populations. "[E]ven female choice against chemically tainted birds, as is the case with the Hudson River chickadees, can threaten local birds if males don’t seem a good mating prospect and females move elsewhere in search of untainted love, DeLeon says. 'Populations could end up declining and birds might not end up living there.'"

And there you have it. Heartbreak, heartache, and chickadees.

Source: New Scientist

Gender Bender: Only Girls Being Born In Arctic Village

Really want to have a baby girl? Then I have a great place for you to live. In certain villages in northern Greenland, only baby girls are being born. Not only is this creepy, but its super disturbing as well. Altered sex ratios of population severely hinder the ability of the population to survive. And, this isn't just a problem in the Arctic. The ratio of baby boys to baby girls has been declining in the US and other industrialized countries since the 1970s.

Whats causing this crazy imbalance? I did some digging around, and it turns out that PCBs are one of the main chemicals linked to crazy sex ratios. PCBs, or polychlorinated biphenyls, are a class of yucky chemicals that were banned in the 1970s for being persistent organic pollutants (POPs). They are found to bioaccumulate in people and animals. A study that just came out found that women in San Francisco with high levels of PCBs in their bodies who became pregnant were a third less likely to give birth to a baby boy.

PCBs aren't the only culprit, though: studies have also linked dioxins, methylmercury, air pollution from incinerators, maternal exposure to non-ionizing radiation, paternal exposure to high voltages, paternal occupation, and parental smoking, among other things, to lower birth rates of boys.

Even though we can pat ourselves on the back for having banned PCBs, the fact that altered sex ratios seem to be a growing problem should be a warning that we need to take a hard look at our current system of chemical regulation. There are a ton of chemicals that we are exposed to every day that bioaccumulate in our bodies, and we don't know the effects of them.