Sunlight winks from behind the trunks, and sheep trot and trip in green pastures to my right. I switch my bike mode to “power” and speed off through the countryside, legs pumping, streaming beneath low-slung gum trees. I’m used to riding my bike in car-choked New York City out here, with no cars in sight and nothing but a dirt road before me, I become 12 again. With a few instructions from our guide Michael from Exceptional Kangaroo Island, we’re off. There are four of us here together, and to get a sense of the island, we swap our van for electric trail bikes. I have never seen a kangaroo in the wild before, and here they feel omnipresent: pausing their feeding in a field to turn and stare, napping by a burbling river, bouncing off into the seemingly interminable distance.įrom the airport, we drive toward the Cygnet Valley, an area of the island known for its conservation park and red gum trees, which line the Cygnet River.
The island off Australia’s southwest coast-a 35-minute flight from Adelaide-is well named marsupials here number around 65,000, about 14 times the human population. Instead, I’m immediately distracted by the kangaroos. Several hundred of these chemicals exist and are members of three closely related families:ģ,3',4,4',5,5'-Hexachlorobiphenyl What is Dioxin?ĭioxins refers to a group of toxic chemical compounds that share certain chemical structures and biological characteristics (see figure 1).It’s overcast when I land on Kangaroo Island, so at first I don’t notice the black of the burn.
PCDDs and PCDFs are not created intentionally but are produced as a result of human activities like the backyard burning of trash. Natural processes like forest fires also produce PCDDs and PCDFs. PCBs are manufactured products, but they are no longer produced in the United States. The most studied and most toxic of all dioxins is 2,3,7,8-tetrachlorodibenzo-p-dioxin. In 2012, EPA released an updated IRIS assessment on this chemical. Pure dioxin looks like white crystalline needles. In the environment, however, it generally is dispersed and attached to soil and dust particles and is invisible to the eye. Industrial activities: Dioxin is not produced or used commercially in the United States. It is a contaminant formed during the production of some chlorinated organic compounds, including a few herbicides such as Silvex. Over the past decade, EPA and industry have been working together to dramatically reduce the production of dioxin and its release to the environment.Īlthough environmental levels of dioxins have decreased in the last 30 years, dioxins are extremely persistent compounds and break down very slowly.
In fact, a large part of current exposures to dioxins in the United States is due to releases that occurred decades ago (e.g., pollution, fires).Įven if all human-generated dioxins were eliminated, low levels of naturally produced dioxins would remain.
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