Acute and reproductive toxicity of nano-sized metal oxides (ZnO and TiO₂) to earthworms (Eisenia fetida).

An increase in nanomaterial applications will likely lead to an increased probability of environmental exposures, raising concerns regarding the safety of these materials. Recent studies have indicated that manufactured nanomaterials, such as metal oxides, have the potential to be harmful to aquatic and terrestrial organisms. The majority of nano-metal oxide research addressing potential toxicological issues has been focused in aquatic environments with very little terrestrial data.

Uptake of 17α-ethynylestradiol and triclosan in pinto bean, Phaseolus vulgaris.

Pharmaceuticals and personal care products (PPCPs) have emerged as a group of potential environmental contaminants of concern. PPCPs in soil may enter terrestrial food webs via plant uptake. We evaluated uptake of 17α-ethynylestradiol (EE2) and triclosan in bean plants (Phaseolus vulgaris) grown in sand and soil.

Acute effects of Fe₂O₃, TiO₂, ZnO and CuO nanomaterials on Xenopus laevis.

Metal oxide nanomaterials have exhibited toxicity to a variety of aquatic organisms, especially microbes and invertebrates. To date, few studies have evaluated the toxicity of metal oxide nanomaterials on aquatic vertebrates. Therefore, this study examined effects of ZnO, TiO(2), Fe(2)O(3), and CuO nanomaterials (20-100 nm) on amphibians utilizing the Frog Embryo Teratogenesis Assay Xenopus (FETAX) protocol, a 96 h exposure with daily solution exchanges.

Effects of ZnO nanomaterials on Xenopus laevis growth and development.

The objectives of this study were to quantify uptake and developmental effects of zinc oxide nanomaterials (nano-ZnO) on Xenopus laevis throughout the metomormosis process. To accomplish this, X. laevis were exposed to aqueous suspensions of 40-100 nm nano-ZnO beginning in-ovo and proceeding through metamorphosis.

Effects of functionalized and nonfunctionalized single-walled carbon nanotubes on root elongation of select crop species.

Single-walled carbon nanotubes have many potential beneficial uses, with additional applications constantly being investigated. Their unique properties, however, create a potential concern regarding toxicity, not only in humans and animals but also in plants. To help develop protocols to determine the effects of nanotubes on plants, we conducted a pilot study on the effects of functionalized and nonfunctionalized single-walled carbon nanotubes on root elongation of six crop species (cabbage, carrot, cucumber, lettuce, onion, and tomato) routinely used in phytotoxicity testing.

A cleanup method for perchlorate determination in urine.

There is increasing concern about perchlorate exposure because of perchlorate's potential effects on organisms as a thyroid hormone disruptor, as well as its contamination of the environment being much more widespread than previously thought. Perchlorate is excreted primarily into urine, therefore, evaluating perchlorate residues in urine should be a reasonable approach for determining exposure and if successful could be used as an effective biomarker of perchlorate exposure. Since the presence of ions and other biomolecules in matrices like urine usually confounds accurate determination of perchlorate by ion chromatography, it is necessary to develop efficient methods for perchlorate determination in these matrices.

Preconcentration/preelution ion chromatography for the determination of perchlorate in complex samples.

The determination of perchlorate in complex matrices by ion chromatography (IC) with an online preconcentration and preelution technique is discussed. The method was applied to different sample types containing large concentrations of matrix anions that would otherwise interfere with analysis via conventional IC. The present approach was highly effective in removing most of the matrix anions and was thus resistant to the interferences commonly encountered in a high ionic strength background.

Challenges in determining perchlorate in biological tissues and fluids: implications for characterizing perchlorate exposure.

The ability to measure environmental contaminants in biological tissues and fluids is important in the characterization of exposure. However, the analysis of certain contaminants in these matrices presents significant challenges. Perchlorate (ClO4-) has emerged as a potential contaminant of concern primarily in drinking water and also in contaminated food.

Metals and organochlorine pesticides in caudal scutes of crocodiles from Belize and Costa Rica.

Despite high animal diversity in the Neotropics and the largely unregulated use and disposal of pesticides and industrial chemicals in Central America, few data exist regarding accumulation of environmental contaminants in Central American wildlife. In this study we examined accumulation of metals and organochlorine (OC) pesticides in caudal scutes of crocodiles from Belize and Costa Rica. Scutes from Morelet's crocodiles (Crocodylus moreletii) from two sites in northern Belize were analyzed for metals, and scutes from American crocodiles (C.

Development of an extraction method for perchlorate in soils.

Perchlorate originates as a contaminant in the environment from its use in solid rocket fuels and munitions. The current US EPA methods for perchlorate determination via ion chromatography using conductivity detection do not include recommendations for the extraction of perchlorate from soil. This study evaluated and identified appropriate conditions for the extraction of perchlorate from clay loam, loamy sand, and sandy soils.

Effects of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) metabolites on cricket (Acheta domesticus) survival and reproductive success.

The effect of two major hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) metabolites, hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX), on cricket (Acheta domesticus) survival and reproduction was studied. RDX metabolites did not have adverse effects on cricket survival, growth, and egg production. However, MNX and TNX did affect egg hatching.

Organochlorine contaminants in complete clutches of Morelet's crocodile (Crocodylus moreletii) eggs from Belize.

Seven complete clutches of Morelet's crocodile (Crocodylus moreletii) eggs were collected in northern Belize and examined for organochlorine (OC) pesticide residues. The primary OC detected, p,p-DDE, was found in every egg analyzed (n=175). Other OCs detected included p,p-DDT, p,p-DDD, methoxychlor, aldrin, and endosulfan I.

Optimization of operating conditions for the determination of perchlorate in biological samples using preconcentration/preelution ion chromatography.

Perchlorate originates as a contaminant in the environment from the use of salts in the manufacture of solid rocket fuels and munitions. Monitoring potential perchlorate contamination in the environment is of interest, however, very few analytical methods have been developed for perchlorate determination in biological samples. Analysis of complex samples by ion chromatography is complicated by matrix components that can interfere with perchlorate determination.

Patterns of genotoxicity and contaminant exposure: evidence of genomic instability in the marsh frogs (Rana ridibunda) of Sumgayit, Azerbaijan.

The wetlands of Sumgayit in the Azerbaijan Republic contain complex mixtures of contaminants, including polycyclic aromatic hydrocarbons (PAHs), mercury, organochlorine pesticides, and polychlorinated biphenyls. Marsh frogs (Rana ridibunda) were collected from several contaminated wetlands within the city as well as from two reference sites outside the city. Sediment samples revealed heterogeneous patterns of PAH and mercury concentrations throughout Sumgayit, with the highest levels occurring east of the Sumgayit River, within the industrial zone.

Effects of perchlorate on earthworm (Eisenia fetida) survival and reproductive success.

The effects of perchlorate on earthworm, Eisenia fetida, survival and reproductive success were evaluated using three types of tests: dermal contact (filter paper), sand, and artificial soil. All studies utilized a range of perchlorate concentrations in order to simulate levels that are likely to occur in the environment under different scenarios (typical soil levels vs. spill levels).

Organochlorine pesticides and mercury in cottonmouths (Agkistrodon piscivorus) from northeastern Texas, USA.

Despite their ecological importance and global decline, snakes remain poorly studied in ecotoxicology. In this study, we examined organochlorine (OC) pesticide and mercury accumulation in cottonmouths (Agkistrodon piscivorus) living on a contaminated site in northeastern Texas (USA). Mercury and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) were detected in all snakes examined.

Uptake of perchlorate in terrestrial plants.

Cucumber (Cucumis sativus L.), lettuce (Lactuca sativa L.), and soybean (Glycine max) were used to determine uptake of the perchlorate anion (100 ppb) from sand.

Organochlorine contaminants in eggs: the influence of contaminated nest material.

Snake eggs were placed in a synthetic nest contaminated with known concentrations of six organochlorines (OCs) to evaluate whether OCs from contaminated nest material accumulate in eggs. It was hypothesized that contaminated nest material may have contributed to OC burdens in eggs observed previously. The six OCs tested included lindane, heptachlor, aldrin, dieldrin, endrin, and DDT.