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THE EURASAP WORKSHOP ON AIR POLLUTION & THE NATURAL ENVIRONMENT: BIOLOGICAL MONITORING - PART 2. BIOLOGICAL MONITORING

25-27 April 2001, Sofia, Bulgaria

Prof. Nigel Bell and Linda Davies, Imperial College, London, UK

Biological Monitoring

'Biological' is defined as the science of physical life, dealing with plants and animals, their morphology, physiology, origin and distribution. A monitor is something that gives warning. Biological monitoring uses the responses of living organisms to monitor spatial and temporal change.

Historically, systems like the Hawksworth & Rose1 lichen pollution scale used the presence or absence of selected sensitive species at a location to indicate ambient concentrations of sulphur dioxide. Widespread lichen surveys facilitated a map of Indicator species, which correlated with measured mean winter concentrations of sulphur dioxide to the extent that concentrations could be predicted where measurements were absent. In 1976 in London Laundon2 recorded only nine lichen species, by 1989 surveys by Hawksworth3 in North West London recorded 49 species and over 70 were recorded in Kew Gardens l at year. This substantial increase is related to the enormous change in air quality in recent decades. However, increasing nitrophytic species, abundant algal cover and the disappearance of sulphur tolerant species like Lecanora conizaeoides alerts us to the changing nature of air quality. What do these change mean? In Holland van Herck4 has developed a lichen Indicator Scale for ammonia which is used to alert regulators to areas of eutrophication from intensive livestock farming. In Bulgaria the accumulation of heavy metals in bryophytes, together with measured and modelled data provides low cost wide spatial scale data for the identification of hotspots where limited remediation funds can be directed.

The diversity of plants, animals and fungi considered at the workshop demonstrate the enormous potential for using biomonitoring as part of air quality management programmes but equally it identified a number of important constraints that need to be addressed before we can confidently apply such approaches:

An extensive programme of research into the effects of ozone on over 70 tree species showing visible injury (Swiss Federal Institute of Forestry*) identified several common alterations at cell level caused by ozone. The consistency of the injury correlated with the exposure such that the injuries can be clearly differentiated from any other type of adverse reaction from confounding factors such as drought and disease. Forestry workers are now being trained to look for these symptoms. This type of research links causality to correlation and provides the confidence necessary to endorse the application of biological monitors in air quality and forest management. Visible symptoms are reactions to a pollutant at a concentration and exposure period sufficient to cause obvious damage. There are many such Reactor species the most commonly used species for ozone being Nicotiana tabaccum*.

Deposition, retention and uptake of pollution occur at different rates related to atmospheric conditions and the morphological biochemical attributes of the species. Certain species are particularly well adapted to retain pollutants for long periods due for example to ion exchange capacity. These are called the Accumulators. There is usually a saturation point and often a hierarchy of preferential ability by species to the extent that some species may be completely intolerant of one metal yet have the largest retention capacity of another5. These rates are being determined using modern analytical techniques allowing them to be used as semi-quantitative monitors of toxic substances, particularly radionuclides. Mosses are used extensively in Europe to identify areas of contamination to prioritise remediation work and protect the food chain and ecosystems. What happens above saturation point and how metabolites are affected by accumulated material is still poorly understood and should be co sidered when selecting appropriate monitors.

New techniques and analytical tools are both driving and increasing our scientific knowledge to provide the assurances required by regulators if biological monitoring is to be more widely applied. The success of much of the new legislation will depend on furthering this work and sharing research results. The UK appears to be somewhat behind its European partners in many aspects of biological monitoring at both policy and science levels. We have in place a unique physico-chemical monitoring network that could now be used in research to identify new biomonitors and test protocols and validate and supplement measurement data and protect our health and environment. Biomonitoring provides a long-term sustainable adjunct to physical chemical monitoring.

The Recommendations and Conclusions from the Workshop (EURASAP Newsletter 43) provide a valuable agenda for the development and application of biomonitoring techniques as part of a sustainable and integrated approach to air quality management and biodiversity action plans.

EXAMPLES OF NETWORKS & RESEARCH GROUPS

1. APRIL: Air Pollution Research in London (UK Co-Ordinator )

Steering Committee: Professor Helen ApSimon (Chair -Imperial College, London), Professor Bernard Fisher (Environment Agency & Greenwich University), Dr. Steve Smith (King's College, London),Professor Lord Julian Hunt (University College, London), Professor Mike Batty (University College, London), Dr. Claire Burton (Engineering & Physical Sciences Research Council-EPSRC), Dr. Stephanie Coster (Department of the Environment, Food & Rural Affairs-DEFRA),Dr. Roy Colvile (Imperial College, London), Dr. Janet Dixon (University College, London & DEFRA),Chris Lee (Association of London Government), David Hutchinson (Greater London Authority), Jim Storey (Environment Agency), Linda Davies (APRIL Co-Ordinator Imperial/NSCA)

The APRIL Network brings together academics, national and local government, and other organisations with an interest in London's air quality. Over the past few years a systematic review and assessment of air quality in the city has identified areas where the European Standard's for nitrogen dioxide6 and particulates (PM10)7 for protecting human health are exceeded. Both require action to reduce them. It follows that tighter standards to protect sensitive vegetation and ecosystems are also exceeded but current legislation excludes urban areas at the present time.

The APRIL Natural Environment Group includes many scientists with an interest in biological monitoring as well as conservation agencies, local government and land owners. The Group is chaired by the London Environment Agency's representative, Jim Storey. APRIL members are addressing a programme of research related to current legislative needs in London or indeed any large conurbation, and includes the development of biological monitoring systems. A UK Biological Monitoring Research Group involving scientists from UK universities and research establishments was recently established. Private sector funding to develop a research programme covering deposition, uptake and parameters of harm covering oxides of nitrogen and VOCs8 builds on work initiated by Astra Zeneca, a leading pharmaceutical company, CEH Edinburgh and the University of Plymouth. APRIL members initiated, co-ordinated and contributed to the EURASAP workshop in Bulgaria presenting papers on the following topics:

2. BIOMAP

Lead: Borut Smodis and Robert M. Parr

Background: Biomonitoring of Air Pollution as Exemplified by Recent IAEA Programs

Biomonitoring is an appropriate tool for assessing the levels of atmospheric pollution, having several advantages compared with the use of direct measurements of contaminants (e.g., in airborne particulate matter, atmospheric deposition, precipitation), related primarily to the permanent and common occurrence of the chosen organisms in the field, the ease of sampling, and trace element accumulation. Furthermore, biomonitors may provide a measure of integrated exposure over an extended period of time and are present in remote areas and no expensive technical equipment is involved in collecting them. The accumulate contaminants over the exposure time and concentrate them, thus facilitating analytical measurements. Based on large-scale biomonitoring surveys, polluted areas can be identified and by applying appropriate statistical tools, information can be obtained on the type of pollution sources and on the transboundary transport of atmospheric pollutants. The International Atomic Energy Agency is including the research on biomonitors in its projects on health-related environmental studies. Biomonitoring activities from several co-ordinated research projects on air pollution are and results from an international workshop are presented in the AEAI report. In addition, activities in supporting improvements in quality in participating laboratories are outlined.

1992-2000 Participating Countries: Argentina, Bangladesh, Brazil, Canada, Chile, China, Czech Republic, France, Germany, Ghana, India, Israel, Italy, Jamaica, Netherlands, Norway, Poland, Portugal, Russian F., Slovenia, Sri Lanka, Vietnam, Yugoslavia

A second conference was organised in 2000 for participating countries to present results from the Co-ordinated Research Projects initiated under the IAEA programme. Lichens and heavy metals and radionuclides dominated the research but new species of higher plants and other pollutants were included The conference was held in the Azores and a report presented by Dr. Maria Freitas: DEA-ITN (Nuclear and Technological Institute), Portugal on behalf of the International Atomic Energy Agency (IAEA)