Royal Commission on Environmental Pollution

Thank you for your letter of 19 October 2000 and the opportunity to submit views and information for your coming study on the long-term effects of chemicals in the environment. The RSE welcomes this important proposed study and will be willing to submit evidence to the formal consultation in due course. The preliminary comments below have been compiled with the assistance of a number of Fellows with experience in matters concerning chemistry and the environment.

Topics
The proposed three broad topics identified are important and the topic of the assessment of potential hazards and risk assessment, in particular, is a fundamental one. Specific comments of these three topics are addressed below:

a)   An overview of existing scientific knowledge, and further research needs
An overview of existing scientific knowledge on the long-term effects of chemicals in the environment could consider:

Chemicals that persist either in the environment or within the organism. Of particular importance is the effect of the so-called 'second generation' rodenticides on birds of prey, such as barn owls, red kites and buzzards. There is also increasing concern about the effects of pesticides on frog populations; a short account of the problems faced by amphibians appeared in Nature, (volume 408, page 760), 14th December 2000).

Chemicals that have diffuse and/or diverse effects across ecosystems. Although sulphur deposition is declining, nitrogen oxides deposition is becoming a major contributor to the acidification of ecosystems. However, the underpinning science to quantify the role of nitrogen is weaker than that for sulphur. It is possible that large areas of semi-natural vegetation are subject to nitrogen deposition in excess of critical loads for such ecosystems. Concerns have been raised over the lack of current protocols to reduce these levels in the next decade, as well as the synergistic effects between acidification and eutrophication upon species and ecosystems.

Ozone concentrations within the uplands are also expected to increase and it has been suggested that concentrations of ozone may represent the greatest direct gaseous pollution threat to vegetation, but there has been little assessment made of the effects of ozone on non-crop plants.

In addition, there is some concern that mercury and cadmium contamination from incinerator waste can have both acute and chronic effects on birds. Contamination of peatlands close to industrial centres with nickel, copper, lead and other heavy metals has also recently been identified. Such metals can be released in high concentrations after the peat has had a period of drying out followed by heavy rainfall. These high concentrations of released heavy metals could exceed critical limits locally in river and stream ecosystems and are of concern because heavier rainfall events following periods of relative dryness (or drought) are becoming more frequent with the changing climate. The movement of such metals into freshwater ecosystems therefore needs to be monitored and their effects (both direct and indirect) arising from movement throughout freshwater, riparian and, perhaps, estuarine ecosystems need to be investigated.

Chemicals with a short persistence in the environment but a localised impact. Biocides used as anthelminthics on livestock (e.g. avermectins) persist once excreted and are already known to affect invertebrates, such as dung beetles, which can, for example, have a knock-on effect on bird populations such as choughs. However, it seems that there has been little work on discerning whether there are secondary impacts within the ecosystem. The long-term effects of biocides used against sea lice within salmon farms are presently being addressed by a 3-4 year, research study funded by the Ministry of Agriculture, Fisheries and Food, the Department of the Environment, Transport and the Regions, the Scottish Executive and the Scotland and Northern Ireland Forum for Environmental Research (SNIFFER). The project will consider effects on benthic and pelagic ecosystems, although bioaccumulation through the food chain (on fish-eating birds and mammals such as otters) will not be considered. However, because bioaccumulation may occur research in this area could be considered.

Chemicals that have endocrine disrupting capabilities. The ecological impact of these substances, in terms of effects on population dynamics and species communities, is an area which requires more research. There is evidence that some endocrine-disrupting substances are accumulating through the marine and freshwater food-chains. There is therefore a need to clarify whether these effects are being passed on through the natural ecosystems to top predators like otters or fish-eating birds. This could have implications for the type of antifoulant paints approved for use to prevent the colonisation of marine molluscs on boats. With the use of sewage sludge on forest and agricultural land there is also the need to consider the implications of endocrine-disrupting substances both on the target land and on nearby ecosystems.

The effects of successive generations of chemicals on native biodiversity, including microbial populations in the soil and whether modern chemicals are any more damaging than soil sterilisation techniques, such as methyl bromide, steaming or flame treatment (the last two of which are permitted under organic agricultural regimes).

There might also be merit in some consideration of bioremediation to degrade otherwise persistent chemicals in the environment. A recent report in Science has indicated that bioremediation using genetically manipulated micro-organisms, or plants exhibiting root hypertrophy, may be appropriate mechanisms by which to degrade or absorb target chemicals in large volumes of topsoil.

There are also gaps in the types of current assessments made on the use, disposal and movement of chemicals through ecosystem. Current assessments tend to focus on the direct lethal effects. However, consideration need to be also given to sub-lethal impacts on the population dynamics of certain indicator organisms, as well as to the more widespread ecosystem effects. In other words, assessments and the regulatory system need to take a more holistic view of the effects of environmental chemicals on ecosystems, including freshwater and marine ecosystems and the soil. Surprisingly little is known about the effects of environmental chemicals on the soil ecosystem, (which is important in the decomposition of many organic substances), in the cycling of nutrients, and as a first stage in the hydrological cycle.

In terms of assessment methodology, a popular methodology is one based on the systems approach and adopted by the chemical industry (and nuclear, offshore industries). It is known as the goal setting approach which uses the safety case concept. In this approach, hazards are identified and their significance determined by risk assessment and risk levels reduced as appropriate, while a management system is used to ensure that the risk level is maintained at the agreed acceptable level. This method has good features. For example, the operator of the installation has a greater role and the process allows effort to be focused on hazards with intolerable risk levels. But it also has major drawbacks, such as risk is a subject not well understood and can lead to incorrect applications and making comparison of safety cases can be difficult. For this reason, attention should also be given to a collaborative methodology called "Responsibility Sharing Management" (RSM) approach. The approach has the principal features of the goal setting approach but incorporates an extra element which encourages the prescriber, operators and other interested stakeholders to share the responsibility. In this way the solutions derived have been more fully explored. The process is also iterative, with performance measurement and review present to ensure continuous improvement. The RSM approach has been applied to ship safety and engineering education, (see for example Kuo, C., Cojeen, H P "Responsibility Sharing Management (RSM) of Ship Safety", Transaction or Society of Naval Architects & Marine Engineers, Vol. USA, 2000).

Additional Information
I would also like to draw attention to the following Royal Society of Edinburgh responses which are of relevance to this subject: The Basis for Environmental Standards (January 1996); National Waste Strategy: Scotland (July 1999); Study of Environmental Planning (October 1999); and Study of Environmental Planning (July 2000). Copies of the above publications are enclosed with this response and further copies of this response and those above are available from the Research Officer, Dr Marc Rands (email: mrands@rse.org.uk).

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