Environmental monitoring: A changing challenge

The editorial in the inaugural February 1999 issue of JEM stipulated the following goal: “JEM is dedicated to all aspects of the measurement of chemical, physical and biological agents in outdoor, indoor and workplace environments, with a view to assessing exposure in relation to adverse environmental and health effects”. In the context of this broad scope, it is not surprising that environmental monitoring has experienced considerable development in the 10-year interim. Some of the more striking advances reflected in the pages of JEM are highlighted in this perspective.

Spatiotemporal monitoring has found extensive application in measurements of the upper atmosphere, in personal air sampling (indoor, outdoor, and the workplace) and in analyses of soil, vegetation, sediments, and water (ground, surface and potable). Clearly, technical developments and global positioning systems (GPS) has constituted a major driving force, which permits one to combine direct-reading exposure and geographic location assessments with activity patterns. Technical developments in improving online-determinations also occurred concomitantly. An important priority is to integrate and coordinate environmental monitoring and research networks on regional, national and international levels. Assessment of nutrient losses from European catchment areas is an example. This facilitates study of entire ecosystems, which will be crucial in climate change impact studies.

Nanoparticles (dimensions of 1–100 nm) and nanotechnology burst on the scene during the last decade. They do not constitute new forms of materials, as they exist in nature as biogenic matter or as byproducts of the weathering of rocks. Synthetic nanoparticles consist of inorganic substances, ceramics or carbon. Among their uses is the development of new miniaturized sensors and environmental monitoring devices. Clearly, the focus of nanoparticle research and the related publications is multi-dimensional: new preparation methods and applications; their sampling, measurement and characterization; migration and fate in air, aquatic systems (including drinking water), soils and sediments; as well as their routes of entry, absorption by and toxicity to organisms (including humans). Not surprisingly, these developments require new micro-analytical techniques and instrumentation.

Elemental speciation/fractionation of airborne particulates, especially with a focus on workplace samples, has been a topic in JEM articles throughout its publication history. Newer techniques such as X-ray absorption fine structure (XFAS) and absorption near-edge structure (XANES) spectroscopy have been helpful. Speciation/fractionation studies have been extended to urban and landfill air, soils, plants, surface water and tissues (including human).

Advances in polymerase chain reaction (PCR) technology have made available sensitive, accurate, rapid and quantitative identification of micro-organisms. The primary development is referred to as real-time PCR. A fluorescent reporter molecule is employed to monitor the progress of a PCR reaction and circumvents the need to use gel electrophoresis at the end-point of the PCR reaction. Typical applications are for the detection and characterization of toxigenic fungi (moulds) in house and building dust (airborne and on surfaces) and bacteria in air and in drinking and recreational water. By contrast, bioluminescence generated by bacteria, algae, or transfected cells, are useful in quantifying dioxin-like chemicals in sample extracts. Biosensors for determining toxic chemicals and measuring genotoxicity have also been developed.

Until recently, a suite of persistent organic substances has been measured in conventional media (i.e., air, sediments, soil, and water and foods). The majority of these substances were organochlorines including polychlorinated biphenyls (PCBs), dioxins and pesticides. Contaminants which have received less attention are referred to as ‘emerging organic pollutants’ and include as major players brominated flame retardants [of which the polybrominated diphenylethers (PBDEs), polybrominated biphenyls (PBBs) and tetrabromobisphenol A constitute major classes], as well as perfluorooctane sulfonate (PFOS) and other per- and polyfluorinated alkyl substances. Additional emerging substances are: airborne allergenic proteins (e.g., in grain dust), enzymes (e.g., in industrial settings), and endotoxins (e.g., microbial lipopolysaccharides); and pharmaceuticals in aquatic environments such as common drugs and synthetic fragrances from household personal care products. Levels of the contaminants referred to above are extensively measured in tissues of sentinel organisms and receptors in the context of exposure and toxicity assessments. The tissue-residue approach is considered to reflect the target dose better than concentrations in the exposure media.

This snapshot of the topics covered in the first 100 issues of JEM clearly illustrate that it has achieved its initial goal. The multiple exposure media, agents and receptors that are being studied and monitored, along with new developments in technology and modelling, all ensure that the field of environmental monitoring will continue to expand. No doubt, this will be spurred on by the increasing level of anthropogenic activity and the expected consequences of global climate change.

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