Being a scientist in Canberra presents a unique opportunity not only to work with top-notch people at universities, but also in government and consulting. Murrang Earth Sciences has been running for ten years now, and in this time, I’ve learnt of a variety of problems regarding how we address and approach pollution problems, including contaminated lands. In this blog, I aim to summarise these problems. Before I start, a shout out to all those who’ve highlighted these issues with me over the last decade. I hope I’ve done you and the issues you’ve raised justice.
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There is a diversity of routes by which people come into the field of pollution to work within disciplines such as contaminated lands, chemical risk assessment, and regulatory science. Many come through degrees in geology, learning about rocks and soils; others via chemistry, covering analytical chemistry and even pharmacology. I even know people who have come to work in pollution science through degrees in law and social science. I personally came via ecology, having realised I didn’t mind the chemical aspects of ecosystem sciences where most others did.
Not one of these paths teaches all of the necessary tools to understand pollution in reality. The risks chemicals present to the environment, for example, are assessed through a process of chemical risk assessment, where the fate and behaviour, exposure, and receptors (including endpoints) of chemicals are elucidated. All the chemical risk assessors I know, both in government and the private sector, are self-taught, with no academic pathway—through chemistry degrees, environmental degrees, or otherwise—into this critical area of expertise. While these self-taught experts can now train others, such training is approximated to take at least five-years post university. That’s a lot of time to invest in people who might leave the job at any time.
Another problem is that chemical risk assessment experts I know are at least in their fifties, with what I hope is a glorious retirement ahead in the not-too-distant future. This is a very big problem for us in Australia, however, as it means that in Australia at least, there is no one coming through the ranks to ensure that the chemicals and products containing chemicals (that is, pretty much everything) we use present an acceptable risk to human health and the environment. Herbicides, pesticides, and industrial chemicals need to be assessed by people with the appropriate training prior to their acceptance on the Australian market; without this training, unacceptably hazardous chemicals can be used.
Even where scientists become expert ecotoxicologists or environmental chemists, few are trained to understand how governments make decisions about chemicals and what type of data and science governments need to use in their decision-making processes. A government project on which I worked, for example, saw me review a number of scientific research articles outlining the lethality of a chemical on different insect species. Most papers I reviewed never established what lethality would look like, however: after years of papers published on the subject, a scientist found that the chemical would merely paralyse insects for a few days, giving the appearance of lethality but leaving a few to survive and potentially recover. This meant the lethality assessed in prior studies could not be relied upon, as most never stated when and how lethality was measured and I could not be sure the insects assessed were truly dead.
Many people working in applied aspects of pollution science, such as those undertaking contaminant lands assessments, have a poor understanding of the legislative hierarchy within which they work. The legislative hierarchy dictates what rules people must abide by in order to adhere to the law (e.g., acts, regulations), and which are examples of how one might abide by the law (e.g., guidelines and policies). The poor understanding of legislative hierarchy sees needlessly ardent or inappropriate adherence to policies and guideline values, where other lines of evidence indicate a more appropriate decision should occur. For example, the current National Environment Protection (Assessment of Site Contamination) Measure 1999 states an acceptable lead concentration of 300 mg/kg in a residential context. Current research by expert scientists in this field, however, shows that there is no safe limit for lead exposure. I’ve used this research to show that whatever the guideline may be, an unacceptable health hazard is presented when elevated levels of lead occur in soils. It can go the other way though, with copper and arsenic naturally elevated above background levels in the ACT. This means that local environments can be considered to have adapted to arsenic and copper concentrations above adopted guideline thresholds, with these chemicals not presenting an unacceptable risk to human health and the environment in such scenarios.
These are other problems with our pollution training. Substances like herbicides and dry-cleaning liquids are made up of mixtures of chemicals, not the individual chemicals we assess. Few of us understand the implications of such chemical mixtures, let alone how to assess them. Non‑intentional by-products―those that are the result of chemical reactions during substance manufacture—are also not assessed as part of chemical risk assessment and are sometimes unknown inclusions within substances submitted to regulatory authorities for such assessment. Also, many of us are challenged to understand a chemical risk in context: there are all sorts of policies and guidelines related to asbestos, for example. There are very few policies around endocrine disrupting chemicals, however, despite the weight-of-evidence showing these chemicals are having major negative impacts on human populations, with investigations into the environmental impacts only just now being initiated. On the balance, I consider the risks presented to human health by asbestos far lower than the risks presented by endocrine disruptors. Who is assessing for endocrine disruption, however? No one I know, outside a few research projects run by government or academics. I feel like asbestos is constantly being raised for assessment, however, despite its hazards being minimal when it is buried or when it occurs in bound form.
These gaps in our training and expertise are considerable and important. Pollution is one of nine factors considered to critically influence long-term human survival and one of five for which the threat of impacts are considered unacceptably high, the others being climate change, biosphere integrity, biogeochemical flows, and land-system change. Already, the reproductive effects of pollution indicate our ability to have children will decrease to the extent that this will not be possible for most people without medical intervention by the 2050s. And that’s in the populations for which resources are available to assess for such impacts; who knows what’s happening in the poorer countries and in the waterways receiving pollution from sewage treatment plants. These facts alone indicate there is a critical need for better skills, capability, and capacity to assess pollution. I think it likely that research will uncover even greater reasons for urgency in time.