Those who follow environmental matters will be aware of the Dirty Dozen chemicals that were the subject of the Stockholm Convention on Persistent Organic Pollutants, concluded in 2001. Most would be hard-pressed to name more than a few of them, however.
They are Aldrin, Chlordane, Dieldrin, Endrin, Heptachlor, hexachlorobenzene, Mirex, Toxaphene, polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), polychlorinated dibenzo-p-dioxins (dioxins) and polychlorinated dibenzofurans. Why people can’t remember these names beats me.
Such chemicals persist in the environment, can accumulate in the food chain, and are believed or proven to cause cancer or other serious health effects in both animals and humans. Most of the Dirty Dozen were banned outright under the Stockholm Convention, which came into effect in 2004 and was signed, ratified, or otherwise acceded to by 180 countries. The rest were severely restricted. For example, DDT is only permitted for limited use in malaria control.
The United States is a notable exception to the list of ratifiers, but then, it had already banned most of these chemicals between the late 1960s and the early 1990s. It also passed a law in 1980, the Comprehensive Environmental Response, Compensation, and Liability Act, better known as the Superfund, to pay for the clean-up of polluted sites. If they can be identified and held liable, responsible parties cover the costs, but taxpayers are on the hook for a billion dollars or two every year.
The number of new clean-up sites has been decreasing, mostly because the worst cases have been dealt with. The environment today is much cleaner than it was 40 or 50 years ago, and new cases of significant pollution are much less common. The environmental movement, for all its faults, can consider toxic pollution an area where they have been successful in creating awareness and prompting action.
The new buzzword in environmental clean-up – or remediation – circles is PFOS. This stands for perfluorooctanesulfonic acid, which repels both water and fat, and was the key ingredient in Scotchgard fabric treatment. It is also used in fire-fighting foam and for spray suppression in chrome-plating metal, which are the most common sources for PFOS in the environment. Other uses are in aviation hydraulics, semiconductors, textiles, paper, leather, wax, polishes, paints, varnishes, and cleaning products for general use.
The primary manufacturer, 3M, announced a phase-out in 2000, soon after its presence was detected in human blood, even though few people were exposed to high levels outside those at occupational risk of exposure, and levels had already been declining.
It has since been added to the Stockholm Convention list of persistent organic pollutants, and was restricted to closed-system uses such as hydraulics and semiconductor manufacturing. Alongside it, 13 other substances have been banned. In short, the list of pollutants on which every member country to the convention has to act is growing.
This does not only affect new pesticides, cleaning compounds, consumer products and industrial chemicals, which only seems sensible. It also means that remediation companies are sniffing out new sites of contamination which they can get to clean up, often at very significant expense either to industry or to the taxpayer.
A recent conference organised by the Australasian Land and Groundwater Association, at which I had the pleasure to speak, was attended by many companies that specialise in the remediation of soil and water. They knew a lot more about the subject than I did, and how they go about the complex work of decontaminating affected sites was quite impressive.
What I also noticed, however, was a sense of excitement about their business. While the rest of the world economy is pretty down in the dumps, if you’ll excuse the pun, this industry is in high spirits. Despite the fact that the low-hanging fruit of the Dirty Dozen had mostly been picked, and the world is a much cleaner place than it was a few decades ago, the remediation business is booming.
Several people commented to me that they thought the PFOS scare was overblown. They were also fairly critical of environmentalists and the media who, they said, were liable to instil fear and distrust among the public, rather than informing them of the real dangers. Many appreciated the angle I take in my talks, that environmental exaggeration is harmful, especially to emerging economies, and that one should distrust environmental activists just as much as one would distrust corporate spin.
However, they said they weren’t complaining, because it meant more work for them. Site assessment and remediation is big business. In the US alone, it is worth $18-billion per year, and is predicted to grow significantly.
What made me think the pendulum might be swinging too far was an undertaking at the conference to identify, catalogue and assess every single underground storage tank. These are most obviously used by petrol stations, but factories and other industrial plants also use them for chemical storage.
Some of them, no doubt, leak. This results in what they call hydrocarbon plumes, which spread contamination into surrounding soil and groundwater. If the site is near a river, these plumes can also contaminate surface water.
On the face of it, this might be a concern. However, one session noted that hydrocarbons are among the pollutants that can be left to natural microbial biodegradation. Hydrocarbons are not uniquely man-made chemicals; they exist in nature, and some organisms have evolved to feed on them. When the Deepwater Horizon disaster happened, clean-up operations were prominent in the media, but few reported that remediation accounted for only about a third of all the oil released into the Mexican Gulf. The remainder was broken down by natural processes of sea, sun and microbes. There are many so-called bio-remediation techniques that rely on such natural processes.
Another talk questioned the value of human health impact studies, on the grounds that exposure levels are often so low as to make the risk hard to measure. As Paracelsus, the founder of toxicology, observed six centuries ago, the dose makes the poison.
Surveying underground storage tanks might be an option in a rich country like Australia, but the Stockholm Convention with its growing list of undesirable chemicals applies to middle- and low-income countries too. In South Africa, we’re fighting disease, childhood mortality, malnutrition, poverty, indoor air pollution, unemployment and students who want to extort free higher education out of the taxpayer. Petrol stations are already highly regulated by government. Is it really worth investing fortunes into efforts to poke around at each one, just in case there is some contamination we can pay a remediation company to clean up?
Pollution is a genuine concern, and efforts at preventing new pollution, and cleaning up the worst old pollution, are to be welcomed. But rich countries and the rest of us have different priorities. When the remediation industry is one of the few that’s booming, one wonders whether the limited resources we can throw at humanity’s problems are being spent in the most productive way. Maybe I’m just in the wrong business. DM