State of research: environmental pathways and food chain transfer.

Abstract

Data on the chemistry of biologically active components of petroleum, synthetic fuel oils, certain metal elements and pesticides provide valuable generic information needed for predicting the long-term fate of buried waste constituents and their likelihood of entering food chains. Components of such complex mixtures partition between solid and solution phases, influencing their mobility, volatility and susceptibility to microbial transformation. Estimating health hazards from indirect exposures to organic chemicals involves an ecosystem's approach to understanding the unique behavior of complex mixtures. Metabolism by microbial organisms fundamentally alters these complex mixtures as they move through food chains. Pathway modeling of organic chemicals must consider the nature and magnitude of food chain transfers to predict biological risk where metabolites may become more toxic than the parent compound. To obtain predictions, major areas are identified where data acquisition is essential to extend our radiological modeling experience to the field of organic chemical contamination.

Environmental Challenges Threatening the Growth of Urban Agriculture in the United States

“…Moreover, soil and plant concentrations of PAHs are not always correlated (Wild et al, 1992;Wild and Jones, 1993). Previous studies suggest that atmospheric deposition and sorption of PAHs on plant foliage exceeds root uptake of PAHs from the soil (Matzner, 1984;Vaughan, 1984); thus, the use of physical barriers (e.g., high tunnels and row covers) may be effective in mitigating PAH deposition on urban crops and subsequent human exposure. In addition, atmospheric deposition of PAHs gives urban farmers another reason to follow best management practices and thoroughly wash all produce before sale and consumption (USEPA, 2011).…”