A quantity of miscible contaminant gas is released into the atmospheric boundary layer and the objective is to describe the evolution of contaminant concentration values within the cloud. Although turbulent convective motions will spread the contaminant cloud over distances of tens of meters the only mixing between host and contaminant fluid, and hence reduction of concentration values, takes p...

For T > 0, fixed, let UT = U × 0,T where U denotes a bounded open set in Rn.Suppose that U is filled with a material in which a contaminant is being transported by various means including diffusion and convection. Let the concentration of contaminant at x, t in UT be denoted by ux, t and let the vector field F⃗x, t denote the flux field for the contaminant. Then we can state a conservati...

Levels of chlorinated organic contaminants in predator fish have been monitored annually in each of the Great Lakes since the 1970s. This article updates earlier reports with data from 1991 to 1998 for lake trout (Salvelinus namaycush) and (Lake Erie only) walleye (Sander vitreus) to provide a record that now extends nearly 30 years. Whole fish were analyzed for a number of industrial contamina...

BACKGROUND Organochlorine contaminants (OCs), like polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethanes (DDTs), are widespread marine pollutants resulting from massive historical use and environmental persistence. Exposure to and health effects of these OCs in the marine environment may be examined by studying California sea lions (Zalophus californianus), which are long lived,...

Background: Evaluation on the toxicity of two mainly contaminant heavy metals, cadmium (Cd) and lead (Pb) through the food chain was the aim of this study. Methods: A total number of 270 healthy common carp (4±1.14 g) in April, 2015 transported to the Khatam Alanbia University of Technology, Behbahan, Iran. Fishes were divided into three groups and transferred to the 20 L aquaria each...

For the first time, scientists have compared a woman’s daily intake of iodine and perchlorate with the concentrations of each in her breast milk. They found that a small proportion (about 20%) of iodine enters the breast milk compared with a higher proportion (more than 50%) of perchlorate. Although not definitive, experts say the study, published in ES&T (DOI 10.1021/es801549w), provides furth...

BACKGROUND The health benefits of organic foods are unclear. PURPOSE To review evidence comparing the health effects of organic and conventional foods. DATA SOURCES MEDLINE (January 1966 to May 2011), EMBASE, CAB Direct, Agricola, TOXNET, Cochrane Library (January 1966 to May 2009), and bibliographies of retrieved articles. STUDY SELECTION English-language reports of comparisons of organi...

The global spread of invasive species is changing the structure of aquatic food webs worldwide. The North American Great Lakes have proved particularly vulnerable to this threat. In nearshore areas, invasive benthic species such as dreissenid mussels and round gobies (Neogobius melanostomus) have gained dominance in recent years. Such species are driving the flow of energy and material from the...

Polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzo-p-furans (PCDD/Fs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane diastereomers (HBCDs), and perfluorinated compounds (PFCs) were analyzed in popular farmed fish such as salmon, trout, tilapia, and pangasius and in farmed shrimp. The samples originated from southeas...