Of all the waste materials included in the Bophary shipment, by far the most dangerous
are polychlorinated biphenyls, or PCBs.
PCBs are one of the Persistent Organic Pollutants (POPs), targeted for global phase-out,
and one of the 12 substances most wanted for elimination under the Basel Convention
on hazardous waste.
PCBs are highly stable heat conductors - they don't break down easily. Because of
this they make an ideal fluid for insulating electrical transformers and capacitors.
Unfortunately, for the same reason, they are environmentally very unfriendly - once
released into the environment they are very difficult to get rid of.
Characteristics of PCBs are similar to those of dioxins. According to the Environmental
Protection Agency of the United States, "chronic exposure of animals to PCBs
can lead to disrupted hormone balances, reproductive failures, teratomas (a type
of tumor), or carcinomas (cancers)".
PCBs are soluble in fat. This means they tend to accumulate in living things once
they enter the food chain.
Larger, older predators tend to accumulate PCBs in their fatty tissues, including
their eggs (in the case of birds and fish) and their milk (in the case of mammals).
Symptoms of exposure include swelling of the eyelids, pigmentation of the nails and
mucous membranes, fatigue, nausea and vomiting, and rashes.
More alarming long-term effects have been documented, including poor cognitive development
in children born up to seven years after the mother was exposed to PCBs.
The whereabouts of 30 percent of all PCBs in the world (nearly 50 million tonnes),
remains unknown. Another 30% resides in landfill, in storage, or in the sediments
of lakes, rivers and estuaries. The balance are still in use.
PCTs ( Polychlorinated triphenyls) and PBBs (polybrominated biphenyls) are very similar
in chemical make-up. They are generally regulated in the same way and under the same
laws as PCBs.
Disposal of PCBs is divided into two categories. Those low-level PCBs (50 parts per
million or less) are considered safe for landfill. High level PCBs (above 50 ppm)
should be incinerated in extremely high temperatures: 4,000 degrees F (2,200 degrees
celsius).
Part of the Bophary shipment includes waste electric transformers containing PCBs.
This is the primary source of PCBs - transformers and condensers being taken out
of service.
Asbestos
A very well-known carcinogenic hazardous waste, asbestos is the name applied to a
group of six different minerals that occur naturally in the environment. The minerals
are made up of long, thin fibers that appear somewhat similar to fiberglass. Asbestos
fibers are very strong and are resistant to heat and chemicals, and so are used in
a wide variety of products, mostly in building materials, friction products, and
heat-resistant fabrics. Because the fibers are so resistant to chemicals, they are
also very stable in the environment. They do not evaporate into air or dissolve in
water and they are not broken down over time.
Asbestos can be ingested through breathing in fibers in the air, or through drinking
water contaminated with the mineral. There is no known safe exposure of asbestos,
but symptoms may not appear for 20 to 30 years after contamination. Diseases caused
by asbestos include lung cancer, especially mesothelioma, and asbestosis, a condition
caused by reduced blood flow to the lung and an enlarged heart. Both diseases are
fatal.
In places such as India, asbestos is regularly recycled and used in building materials.
Waste tarry residues arising from refining, distillation and any pyrolitic treatment
of organic materials.
According to Jim Puckett of the Basel Action Network, this could be highly hazardous
material, containing dioxins or furans. Again, with no details on the document, it
is hard to say just how noxious the substance is.
Ceramic-based fibers of physicochemical characteristics similar to those of asbestos
These are considered to be just as hazardous as asbestos by environmental professionals,
and appear on the OECD red list of hazardous wastes.
Waste lead-acid accumulators
These are lead-acid batteries, usually coming from motor vehicles. Their lead and
sulfuric acid content, and their propensity to cause contamination when recycled,
qualify them as a hazardous waste. Proper disposal would entail professional recycling.
Used electrical equipment
Dangers are the hazardous components, including heavy metals, PCBs, PBS and PCTs.
Contact PhnomPenh Post for full article
Post Media Co LtdThe Elements Condominium, Level 7
Hun Sen Boulevard
Phum Tuol Roka III
Sangkat Chak Angre Krom, Khan Meanchey
12353 Phnom Penh
Cambodia
Tel: +855(0) 23 888 161 / 162
Fax: +855(0) 23 214 318