Killer whales: why more than half world’s orcas are threatened by leftover industrial chemicals

These chemicals were produced in immense quantities from the 1930s onwards and were broadly phased out in the 1970s/1980s as environmental concerns grew. As they were very stable and were unable to conduct an electrical current (and therefore excellent insulators), they were mainly used in the electrical supply industry. These same properties also saw them being used in a whole array of miscellaneous applications including as sealants and additives in construction. It is this chemical stability that means PCBs stubbornly refuse to degrade in the environment and I have spent the past 25 years studying how these and other contaminants end up accumulating in the Arctic, for instance.

A solution that uses toxic waste to clean up toxins

Our research group at the Hong Kong University of Science and Technology has developed an innovative chemical process that alters the surface of this low-value waste material and converts it to a nanoporous material.

Even animals deep below the ocean are being poisoned by toxic chemicals

Deep sea exploration uncovers crustaceans poisoned by PCBs.

From Industrial Toxins to Worldwide Pollutants: A Brief History of Polychlorinated Biphenyls

Today, PCBs, chemicals that were virtually unknown in the late 1920s and that became mass produced only in the early 1930s, have become worldwide pollutants and judged probable human carcinogens.

Some Tuna Can Carry Up To 36 Times The Toxic Chemicals Of Others. Here's Why

Most of the tuna analyzed would be considered safe under current EPA/FDA joint consumption advice, but there were concerns. The study found that 90 percent of tuna caught in the northeast Atlantic Ocean — and more than 60 percent of yellowfin samples caught in the Gulf of Mexico — contained pollutant levels that would have triggered health advisories in some segments of the population, including pregnant and nursing women.

The Toxins That Threaten Our Brains

Leading scientists recently identified a dozen chemicals as being responsible for widespread behavioral and cognitive problems. But the scope of the chemical dangers in our environment is likely even greater. Why children and the poor are most susceptible to neurotoxic exposure that may be costing the U.S. billions of dollars and immeasurable peace of mind.

What are PCBs?

PCBs can degrade or breakdown in the environment, but the process greatly depends on the chemical makeup of the PCBs. The degrading process also depends on where the PCBs are in the environment. Typically, PCBs are either broken down in the environment by sunlight or by microorganisms. Sunlight plays an important role in the breakdown of PCBs when they are in the air, shallow water, or surface soils. Microorganisms, such as bacteria, algae, or fungi, biodegrade PCBs when found in soil or sediments.

Why Are Researchers Looking At Links Between Banned Chemicals And Autism?

The awful thing about PCBs and similar compounds is their affinity for fat once an organism takes them up. That means that the higher up the "food chain" an organism sits, the higher the concentrations of these things it will probably have. And PCBs are everywhere, especially finding their way via these "top feeder" animals to the polar regions, where the people who subsist on these animals themselves have high PCB concentrations. As a sort of coup de grâce, PCBs also can take anywhere from months to years and years to break down, so they stick around, causing the problems they cause. What seems unclear, though, is why anyone thinks they would be associated with autism.