Daily stream samples reveal highly complex pesticide occurrence and potential toxicity to aquatic life.

Transient, acutely toxic concentrations of pesticides in streams can go undetected by fixed-interval sampling programs. Here we compare temporal patterns in occurrence of current-use pesticides in daily composite samples to those in weekly composite and weekly discrete samples of surface water from 14 small stream sites. Samples were collected over 10-14 weeks at 7 stream sites in each of the Midwestern and Southeastern United States.

Occupational safety training and education for needlestick injuries among nursing students in China: intervention study.

Objectives: To confirm the effect of occupational safety training and education programs (OSTEP) on needlestick injuries (NSIs) among nursing students in China.

Methods: Compare the rates and the nature of NSIs before and after OSTEP among the nursing students in China. Firstly, questionnaires were delivered to 248 randomly selected nursing students from seven training hospitals to obtain basic information concerning relevant occupational NSIs.

Evaluation of the permeability of agricultural films to various fumigants.

A variety of agricultural films are commercially available for managing emissions and enhancing pest control during soil fumigation. These films are manufactured using different materials and processes which can ultimately result in different permeability to fumigants. A systematic laboratory study of the permeability of the agricultural films to nine fumigants was conducted to evaluate the performance of commonly used film products, including polyethylene, metalized, and high-barrier films.

Gestational atrazine exposure: effects on male reproductive development and metabolite distribution in the dam, fetus, and neonate.

Few studies have investigated the long-term effects of atrazine (ATR) following in utero exposure. We evaluated the effects of gestational exposure of Sprague Dawley dams to ATR (0, 1, 5, 20, or 100mg/kg-d) on the reproductive development of male offspring. We also quantified the distribution of ATR and its chlorinated metabolites in maternal, fetal, and neonatal fluid and tissue samples following gestational and/or lactational exposure.

Development and validation of a multiresidue method for the determination of neonicotinoid and macrocyclic lactone pesticide residues in milk, fruits, and vegetables by ultra-performance liquid chromatography/MS/MS.

A multiresidue method was developed and validated for the determination of 13 neonicotinoid pesticides and metabolites, and nine macrocyclic lactone pesticides and veterinary drugs using SPE and ultra-performance liquid chromatography/MS/MS. The method was validated in milk, orange, spinach, apple, plum, watermelon, green bean, zucchini, broccoli, strawberry, grape, and tomato by analyzing replicates of residue-free control samples fortified with a mixture of 22 target analytes at three concentration levels. The recoveries of the analytes from the fortified matrixes were mostly within 70-120%, except for some of the neonicotinoid metabolites.

Needlestick injuries among nursing students in China.

Objectives: To describe and characterize the rates and the nature of needlestick injuries among nursing students in China.

Methods: A questionnaire was delivered to 248 randomly selected nursing students from seven training hospitals to obtain information relevant occupational needlestick injuries.

Results: A total of 1144 incidents of needlestick injuries were reported among the 246 nurses during the time period of internship.

Source characterization using compound composition and stable carbon isotope ratio of PAHs in sediments from lakes, harbor, and shipping waterway.

Molecular compositions and compound specific stable carbon isotope ratios of polycyclic aromatic hydrocarbons (PAH) isolated from sediments were used to characterize possible sources of contamination at an urban lake, a harbor, a shipping waterway, and a relatively undisturbed remote lake in the northwest United States. Total PAH concentrations in urban lake sediments ranged from 66.0 to 16,500 microg g(-1) dry wt.

Comparison of acute neurobehavioral and cholinesterase inhibitory effects of N-methylcarbamates in rat.

While the cholinesterase-inhibiting N-methyl carbamate pesticides have been widely used, there are few studies evaluating direct functional and biochemical consequences of exposure. In the present study of the acute toxicity of seven N-methyl carbamate pesticides, we evaluated the dose-response profiles of cholinesterase (ChE) inhibition in brain and erythrocytes (RBCs) as well as motor activity (both horizontally and vertically directed) and clinical signs of overt toxicity. The chemicals tested were carbaryl, carbofuran, formetanate, methiocarb, methomyl, oxamyl, and propoxur.

Molecular and stable carbon isotopic characterization of PAH contaminants at McMurdo Station, Antarctica.

The molecular and stable carbon isotopic compositions of contaminant polycyclic aromatic hydrocarbons (PAHs) at McMurdo Station, Antarctica were analyzed in samples collected from land and sub-tidal area. PAHs in the study areas were characterized by high amounts of naphthalene and alkylated naphthalenes from petroleum products introduced by human activities in the area. Principal component analysis (PCA) of PAH composition data identified multiple sources of PAH contamination in the study area.

Sorption of organic pollutants by marine sediments: implication for the role of particulate organic matter.

The objective of this study was to quantify sorption properties for kerogen/black carbon (BC)-bearing sediments. Single-solute sorption isotherms were measured for five pristine marine sediments using phenanthrene, naphthalene, 1,3,5-trichlorobenzene, and 1,4-dichlorobenzene as the sorbates. The results showed that the sorption isotherms were nonlinear and that the organic carbon normalized single point K(OC) values were comparable to those reported in the literature for the purified kerogen and BC, but are much higher than the data reported for HA and kerogen/BC-containing terrestrial soils and sediments.

Polycyclic aromatic hydrocarbon purification procedures for compound specific isotope analysis.

Purification and isotope analysis methods were developed to accurately measure the stable carbon isotope ratio of individual PAHs in environmental samples. Sample extracts were separated into several fractions by column chromatography and were purified by high-performance liquid chromatographic and thin-layer chromatographic techniques. The mean recovery of the purification method for all compounds was approximately 80%.

Degradation of picric acid and 2,6-DNT in marine sediments and waters: the role of microbial activity and ultra-violet exposure.

Bio- and photo-transformation of two munitions and explosives of concern, 2,6-dinitrotoluene (2,6-DNT) and 2,4,6-trinitrophenol (picric acid) were assessed in spiked marine sediments and water. A sandy and a fine-grained sediment, with 0.25% and 1.