Monday, May 12, 2014

Dioxins (The Nightmare of incinerating)

 By Bello Adedayo

I went numb as the lecture about the origins and effects of dioxins was delivered in one of my ecotoxicology classes. My mind flashed back to the ignorant behavior in my past adventures while growing up in Lagos, Nigeria. I reminisced about how I and my siblings were always excited when given permission by our parent to burn some old household materials in our backyard. We really got so excited that we went as far as collecting our neighbor’s trash so we could have more stuff to incinerate. We would all gather around the burndrum and watch it burn with so much excitement. That was then; now I know that improper incineration produces very toxic and hazardous chemical compounds called dioxins and furans. 

What do I now know about dioxins and furans?
Dioxins and furans are chemically related groups of chlorinated compounds that have similar chemical and biological properties. Dioxins and furans can be classified into three main groups, which are Polychlorinated dibenzo-P-dioxins (PCDFs), Polychlorinated dibenzo furans (PCDFs) and Polychlorinated biphenyls (PCBs). These compounds are mostly used as chemical raw material in producing many household items, such as clothes, plastic bottles and furniture.

 The presence of these toxic chemical compounds in the environment is caused mainly by human activities, especially during different combustion processes, such as commercial and municipal waste incineration, drum burning of household materials, smoking of cigarettes, and burning of fuel, including wood, oil and coal, to mention a few.     

Why should we be concerned about dioxins and furans?
Dioxins and furans possess chemical structures very similar to those of human hormones such as estrogen and testosterone, which are hormones responsible for sexual and reproductive development in humans.  Because of this similarity in chemical structure, dioxins and furans are able to bind to particular cells in the same way estrogens and testosterones do, but as they are not hormones, when they bind to these cells, a dangerous chain of events starts to happen. These events can eventually lead to reproductive and developmental problems in humans. Dioxins and furans can also damage the human´s immune system and has been proven to be a major cause of cancer.

Fig 1: Chemical structure of a female hormone (Oestradiol)

Fig 2: chemical structure of a dioxin (Octachlorodibenzodioxin)                                

How can this be controlled?
The continuous production of these toxic compounds in the environment can be controlled by proper incineration of chlorinated material, including Polyvinyl-chloride (PVC), which is found in most household items. So if you have old clothes and household rubbish you would like to dispose of, send it to a proper facility where it can be incinerated at a temperature above 850 o C. Please don´t use your burndrum.

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