A method is presented for developing sediment quality guidelines (SQG) for narcotic chemicals in general and polycyclic aromatic hydrocarbons (PAHs) in particular. The guidelines can be applied to any individual or mixture of narcotic chemicals including PAHs using only the chemical’s octanol/water partition coefficient. They are derived using the final chronic values for type I narcotics devel...

The chromosomal multiple antibiotic resistance (mar) locus of Escherichia coli and other members of the Enterobacteriaceae controls resistance to multiple, structurally unrelated compounds including antibiotics, household disinfectants, organic solvents and other toxic chemicals. The Mar phenotype is induced following exposure to a variety of chemicals with aromatic rings.

Consumers are exposed to a diversity of chemicals in all areas of life. Air, water, soil and food are all unavoidable components of the human environment. Each of those elements influences the quality of human life, and each of them may be contaminated. We are exposed to toxic or potentially toxic compounds in many ways in our daily lives and toxicology is clearly a subject of great importance ...

the pg/mL range with in-line preconcentration [5]. During the development of this method at NBS, the factors investigated included: composition of the eluents, interference due to impurities in the delivery liquid and the possible means of eliminating them with a laboratory-packed trap column, and a comparison of suppression efficiencies between two types of suppressors. This method was used fo...

Biological monitoring of exposure to chemicals has the objective of defining the so-called 'internal dose' or 'internal exposure level', and has been attempted by a variety of experimental approaches. Two categorical types of measurements can be made for this purpose: (1) measurement of concentrations of chemicals (or their metabolites) in body fluids or excreta; or (2) measurement of toxicolog...

The positive chemotactic responses of motile marine bacteria were reversed by the addition of sublethal concentrations of a toxic chemical. The negative chemotactic effect was observed with a wide range of toxicants including heavy metals and hydrocarbons. This phenomenon may be utilized to develop new approaches for control of marine fouling.

The kidneys are capable of carrying out extensive oxidation, reduction, hydrolysis, and conjugation reactions. Renal cortex has high activities of cytochrome P450 and glutathione (GSH) S-transferase. In contrast, renal medulla has high activity of prostaglandin synthetase, which can catalyze co-oxidation of xenobiotics. While these pathways are found in many tissues and at higher activities tha...