Jane A. Plant

Cadmium levels in Europe: implications for human health

In this study we used the Forum of European Geological Surveys geochemical baseline data to examine the distribution of cadmium (Cd) in Europe, with a particular reference to the international soil and water guideline values. The highest cadmium levels were found to occur in topsoil and to follow closely the distribution of P2O5, suggesting that the contamination was from the use of rock phosphate fertilizer in intensive arable agriculture. In terms of human health impacts, food (up to several hundred μg/day) was found as the only major route of exposure to Cd for the non-smoking general population. It appeared that low levels of chronic exposure to Cd resulted in completely different human health impacts than those high levels that had caused the ‘itai–itai’ disease. Some correlations were suggested between cadmium levels and the age-adjusted prostate or breast cancer rates distributed in the European countries under study.

Arsenic and selenium

This chapter outlines the main effects of arsenic and selenium on human and animal health, their abundance and distribution in the environment, sampling and analysis, and the main factors controlling their speciation and cycling. Such information should help identify aquifers, water resources and soils at risk from high concentrations of arsenic and selenium, and areas of selenium deficiency. Human activity has had, and is likely to continue to have, a major role in releasing arsenic and selenium from the geosphere and in perturbing the natural distribution of these and other elements over the Earths surface.

Platinum, palladium and rhodium release from vehicle exhaust catalysts and road dust exposed to simulated lung fluids

The risk associated with the inhalation of platinum group element (PGE) emissions from vehicle exhaust catalysts (VECs) has been investigated by extracting road dust and milled auto catalyst with simulated lung fluids. Gambles solution (representative of the interstitial fluid of the deep lung) and artificial lysosomal fluid (ALF) (representative of the more acidic environment within the lung) were employed as extraction fluids. The highest PGE release was observed in ALF, implying that inhaled particles would have to be phagocytized before significant amounts of PGEs dissolve. The greatest percentage (up to 88%) of PGEs was released from road dust, possibly due to the presence of mobile PGE species formed in the roadside environment. Pt showed the highest absolute bioavailability, due to its greater concentration in the environmental samples. Pd and Rh had higher percentage of release, however, because of their more soluble nature. From the toxicological perspective, the results demonstrate potential health risks due to the likely formation of PGE-chloride complexes in the respiratory tract, such species having well-known toxic and allergenic effects on human beings and living organisms.

Calculating human exposure to endocrine disrupting pesticides via agricultural and non-agricultural exposure routes.

Endocrine Disrupting Chemicals (EDCs) are of increasing concern because of their potential impacts on the environment, wildlife and human health. Pesticides and some pesticide metabolites are an important group of EDC, and exposure to them is a poorly quantified source of human and environmental exposure to such chemicals generally. Models for estimating human exposure to Endocrine Disrupting (ED) pesticides are an important risk management tool. Probabilistic models are now being used in addition to deterministic ones in all areas of risk assessment. These can provide more realistic exposure estimates, because they are better able to deal with variation and uncertainty more effectively and better inform risk management decisions. Deterministic models are still used and are of great value where exposure data are scarce. Models or groups of models that provide holistic human ED pesticide exposure estimates are required if the risk posed to humans by ED pesticides is to be better assessed. Much more research is needed to quantify different exposure routes such as exposure from agricultural spray drift and the medical use of pesticides to develop such models. Most available probabilistic models of human exposure were developed in the USA and require modification for use elsewhere. In particular, datasets equivalent to those used to create and apply the American models are required. This paper examines the known routes of human pesticide exposure with particular reference to ED pesticides and their quantification as unlike pesticides generally, many ED pesticides are harmful at very low doses, especially if exposure occurs during sensitive stages of development, producing effects that may not manifest for many years or that affect descendants via epigenetic changes. It also summarises available deterministic and probabilistic models commonly used to calculate human exposure. The main requirement if such models are to be used in the UK is more quantitative data on the sources and pathways of human ED pesticide exposure.

Interpolation methods for geochemical maps : a comparative study using arsenic data from European stream waters

A geochemical map of As in water from the FOREGS Geochemical Atlas of Europe, performed using the Alkemia interpolation method based on moving weighted median (MWM), and a comparable map prepared by kriging are compared with an As map prepared with a new multifractal inverse distance weighted (MIDW) interpolation method using GeoDas™ software. The colour scale classification of the MIDW interpolated map of As is based on the concentration–area (C-A) fractal method which allows images to be subdivided into components representing specific features on the ground related, for example, to geology. Conventional techniques, such as MWM and kriging, are shown to smooth out the local variability of the geochemical data. The problem is most serious in maps prepared by kriging which erroneously show large areas of Europe to have high levels of As in water. On the other hand, MIDW creates a geochemical map in which information about the local data structure is retained. This is essential in distinguishing anomalies from background values. The information provided by background and anomaly maps, using the MIDW and fractal filtering methods, are shown to give more reliable upper limits of background values.

The distribution of uranium over Europe: Geological and environmental significance

Abstract The variation of baseline levels of uranium in soil and stream sediments over Europe is described, based on new data prepared by the Forum of European Geological Surveys (FOREGS). The samples have been collected and analysed according to the protocols established for the International Union of Geological Sciences/International Association of Geochemistry and Cosmochemistry (IUGS/IAGC) Working Group on Global Geochemical Baselines. The baseline levels of U vary between 0·21 to 53 mg kg-1 in topsoils, 0·19 to 30 mg kg-1 in subsoils and < 1 to 59 mg kg-1 in stream sediments. There is generally good agreement between the levels of U in the three sample types, and the median concentration in all three media is approximately 2 mg kg-1. The most anomalous baseline levels occur over the Variscan orogen, especially areas into which late postorogenic radiothermal high heat production (HHP) granites were emplaced. Spiderdiagrams based on trace element levels and rare earth element (REE) plots, confirm the association between the highest U anomalies and evolved radiothermal granites. High values are also associated with parts of the Alpine terrain especially in Slovenia, where there are historical U workings, and Southern Italy, where high values of U reflect contemporary volcanism. In contrast, much of the Caledonides of North West Europe and the Precambrian of the Baltic Shield and East European craton and its overlying sedimentary cover have very low values, generally < 4 mg kg-1. The results suggest that the main concern for the environment and human health from U, and the Th and K with which it is generally associated, is the naturally occurring total gamma radiation and radon potential associated with radiothermal granites. This is likely to be especially important where the granites are mineralised and have been worked historically, for example in the North West of the Iberian Peninsula where U and its decay products are likely to be more dispersed in the surface environment. The study also indicates the value of multielement data in distinguishing between anthropogenic and naturally occurring anomalies.

The rare earth element distribution over Europe: geogenic and anthropogenic sources

The distribution of rare earth elements (REE) in Europe has been investigated using new geochemical data prepared by the Forum of European Geological Surveys (FOREGS), to estimate baseline values and to identify anomalous levels attributable to anthropogenic sources. Interpolated maps showing REE distributions in subsoils were generated using ArcView™ and classified with the new concentration–area (CA) fractal method available in the software GeoDAS™; they identify three broad ranges for baseline REE levels that are related to regional geological/geomorphological features. A combination of REE spider diagrams and interpolated maps showing REE distributions in floodplain and stream sediments was used to investigate anthropogenic sources of REE in Europe. It is concluded that the large-scale distribution patterns of REE over Europe are entirely attributable to geology. No evidence has been found of REE contamination from likely anthropogenic sources such as the electronics or nuclear industry. Three component colour maps of REE ratios (Gd/Lu, Eu/Eu* and La/Y) were used to identify the major plates of the Variscan orogeny and Variscan granites caught up in Alpine nappes in Italy.

Characterisation of carbon nanotubes in the context of toxicity studies

Nanotechnology has the potential to revolutionise our futures, but has also prompted concerns about the possibility that nanomaterials may harm humans or the biosphere. The unique properties of nanoparticles, that give them novel size dependent functionalities, may also have the potential to cause harm. Discrepancies in existing human health and environmental studies have shown the importance of good quality, well-characterized reference nanomaterials for toxicological studies.Here we make a case for the importance of the detailed characterization of nanoparticles, using several methods, particularly to allow the recognition of impurities and the presence of chemically identical but structurally distinct phases. Methods to characterise fully, commercially available multi-wall carbon nanotubes at different scales, are presented.

Chemicals in the environment: implications for global sustainability

Abstract The impact of chemicals on the environment and human health is a cause of increasing concern. Although many studies continue to be carried out on this subject, most address only individual chemicals or particular groups of chemicals, such as metals or radioactive substances. In this paper, we consider the availability of data and knowledge about potentially harmful chemicals from the national to international scale and suggest a strategy to help prevent chemical pollution or deficiencies damaging global sustainability into the 21st century. The main groups of chemicals considered are: (i) Potentially harmful inorganic elements such as As, Cd, Hg and Pb known to have adverse physiological effects at low levels, and elements and species such as Se, I and NOx that can be essential or harmful depending on their concentration, speciation and bioavailability. Chemical elements such as Ga, In and the PGEs that are increasingly used in the development of new materials, including nanotechnology applications, are also discussed briefly. (ii) Radioactive substances, including naturally occurring radioisotopes, such as 238U and its decay products 226Ra and 222Rn, and processed materials, such as depleted uranium (DU), which affect the environment and human health because of their radiological and chemical toxicity. Data on isotopes from the nuclear industry, such as the relatively short-lived isotopes 137Cs and 90Sr, are also discussed, including from accidental releases such as Chernobyl in 1986. Isotopes with longer half-lives such as 243Am and 240Pu, which are important in the development of nuclear waste management strategies are also considered. (iii) Persistent organic pollutants (POPs) including many synthetic chemicals such as dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), flame retardants and their metabolites, which are characterised by their persistence, bioaccumulation (lipophilicity) and toxicity (PBT) properties. Other synthetic chemicals such as perfluorooctane sulphonate (PFOS), which have different bioaccumulation properties, are considered briefly. (iv) Human and veterinary pharmaceuticals, of which there is increasing evidence of their presence in the environment. These substances are of particular concern because many are designed to target specific biological receptors and hence can have potentially deleterious effects at exceptionally low concentrations. All these groups of chemicals include endocrine disrupting chemicals (EDCs), capable of disrupting animal and human hormone systems (including sex and thyroid). Geochemical databases such as those prepared by the Forum of European Geological Surveys (FOREGS) and the British Geological Survey (BGS) provide systematic information on levels of inorganic chemicals in the environment. Similarly, airborne radiometric databases provide systematic information on the distribution of radioactive substances. Examples of such data are used to demonstrate how the distribution of chemicals in the environment can be mapped, and how modelling and monitoring systems derived from them are of strategic importance in understanding the impact of chemicals on ecosystems and human health from the national to global scale. There is concern, however, about the lack of such systematic data for organic chemicals. It is argued that such systematic data for all chemicals is crucial for sustaining the Earths life-support systems into the 21st century.

From chemical risk assessment to environmental resources management: the challenge for mining

On top of significant improvements and progress made through science and engineering in the last century to increase efficiency and reduce impacts of mining to the environment, risk assessment has an important role to play in further reducing such impacts and preventing and mitigating risks. This paper reflects on how risk assessment can improve planning, monitoring and management in mining and mineral processing operations focusing on the importance of better understanding source–pathway–receptor linkages for all stages of mining. However, in light of the ever-growing consumption and demand for raw materials from mining, the need to manage environmental resources more sustainably is becoming increasingly important. The paper therefore assesses how mining can form an integral part of wider sustainable resources management, with the need for re-assessing the potential of mining in the context of sustainable management of natural capital, and with a renewed focus on its the role from a systems perspective. The need for understanding demand and pressure on resources, followed by appropriate pricing that is inclusive of all environmental costs, with new opportunities for mining in the wastes we generate, is also discussed. Findings demonstrate the need for a life cycle perspective in closing the loop between mining, production, consumption and waste generation as the way forward.