A. Wither

Beach sand and the potential for infectious disease transmission: observations and recommendations

Recent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should therefore be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. Here, we review the literature on pathogen levels in beach sand, and their potential for affecting human health. In an effort to provide specific recommendations for sand sampling programmes, we outline published guidelines for beach monitoring programmes, which are currently focused exclusively on measuring microbial levels in water. We also provide background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programmes. First steps toward establishing a sand sampling programme include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand to human health risk.

Setting new thermal standards for transitional and coastal (TraC) waters

The construction of a new generation of coastal power stations in the UK and other western European countries has highlighted the absence of robust standards for thermal discharges to transitional and coastal waters. The proposed discharge volumes are greater than hitherto, yet there has been little independent critical examination of their potential impact, whilst much of the existing guidance has been adapted from freshwater practice. This review considers the available knowledge on the tolerance and behaviour of fish and other marine biota to heated effluents. Appropriate ways are suggested of grouping fish species to reflect their sensitivity to thermal effects. The plethora of existing standards are considered and their validity assessed in a framework of predicted seawater temperature rise. Those species or groups of organisms most likely to be affected are identified and finally specific recommendations for thermal standards consistent with long term sustainability are proposed.

Nutrient inputs to the Irish Sea: temporal and spatial perspectives

Data from five key regions are presented to produce thematic plots of winter nutrient (dissolved available inorganic nitrogen and phosphorus) concentrations for the Irish Sea. It is suggested that riverine discharges are the biggest contributor of nutrients to the system, however, anthropogenic point source discharges are also major contributors of these nutrient salts in the eastern Irish Sea. Comparison of the thematic maps produced in this study are made with similar maps produced almost a decade previously, the comparisons show a great many similarities between the two studies. However, waters in the north-eastern Irish Sea show that dissolved available inorganic phosphorus (DAIP) appears to have decreased in concentration in recent years whilst no such change is seen with respect to dissolved available inorganic nitrogen (DAIN). The use of nutrient-salinity regressions indicate that during winter 1997 anthropogenic discharges along the Cumbria coast combined with remobilisation of sedimented material was a major contributing factor of nutrient salts to the system.