Ex-ante fate assessment of trace organic contaminants for decision making: a post-normal estimation for sludge recycling in Reunion.

The environmental fate of organic waste-derived trace organic contaminants is a recent focus of research. Public awareness of this issue and concern about the potential risks are increasing, partly as a result of this research. Knowledge remains sparse but, due to growing waste volumes and contaminant concentrations, situations are arising where decisions are urgently needed and the stakes are high. We present an approach to provide stakeholders with the soundest possible information on relevant risks in specific situations where local experimental data are scarce or inexistent. With accuracy taking precedence over precision in such situations, the quantitative fate assessment aspect of the approach considers uncertainty at all levels in order to estimate best-to-worst-case (cumulative uncertainty) fuzzy fate ranges. The approach was applied to conditions that prevail on the island of Réunion. Contrasting possible organic residue recycling scenarios are considered in which trace organic contaminants originate either from pig slurry or sewage sludge. The stakeholders' concerns targeted are leaching, soil persistence and crop (sugarcane) shoot translocation. The fate assessment results in soil removal dynamics that vary over a wide range, even for a particular chemical in a particular scenario. For 3 out of 27 chemicals residual soil concentrations after one sugarcane crop cycle could possibly exceed the 100 ng/g dry weight mass fraction range, only in a worst case situation. Substances predicted to be of the highest mobility (erythromycin, ofloxacin, ciprofloxacin) might produce appreciable leaching only in the event of substantial rainfall shortly after a high rate decadal application. And only the higher bound sugarcane shoot concentration estimates of 17 α-ethinylestradiol and tris(chloropropyl)phosphate are significant.

International trade in meat: the tip of the pork chop.

This paper provides an original account of global land, water, and nitrogen use in support of industrialized livestock production and trade, with emphasis on two of the fastest-growing sectors, pork and poultry. Our analysis focuses on trade in feed and animal products, using a new model that calculates the amount of "virtual" nitrogen, water, and land used in production but not embedded in the product. We show how key meat-importing countries, such as Japan, benefit from "virtual" trade in land, water, and nitrogen, and how key meat-exporting countries, such as Brazil, provide these resources without accounting for their true environmental cost. Results show that Japan's pig and chicken meat imports embody the virtual equivalent of 50% of Japan's total arable land, and half of Japan's virtual nitrogen total is lost in the US. Trade links with China are responsible for 15% of the virtual nitrogen left behind in Brazil due to feed and meat exports, and 20% of Brazil's area is used to grow soybean exports. The complexity of trade in meat, feed, water, and nitrogen is illustrated by the dual roles of the US and The Netherlands as both importers and exporters of meat. Mitigation of environmental damage from industrialized livestock production and trade depends on a combination of direct-pricing strategies, regulatory approaches, and use of best management practices. Our analysis indicates that increased water- and nitrogen-use efficiency and land conservation resulting from these measures could significantly reduce resource costs.