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Agricultural pesticide exposure is one factor implicated in the decline of amphibian abundance in aquatic ecosystems. Isoxaben is a cellulose biosynthesis inhibitor mainly used for roadside weed control, suggesting that isoxaben can run off during rain events and potentially affect amphibian development. This study followed the development of African clawed frog (Xenopus laevis) tadpoles exposed to different environmentally relevant concentrations of isoxaben. No significant adverse effects were observed on days to metamorphosis or size and weight at metamorphosis. This reinforces the conclusion that isoxaben herbicide application at low environmental concentrations is not a substantial risk to wildlife. [ABSTRACT FROM AUTHOR]

This study evaluates the cumulative multifactorial physical and chemical impacts resulting from coca production on amphibian populations in comparison with the potential impacts produced by the herbicide glyphosate (Glyphos), which, mixed with the surfactant Cosmo-Flux, is used in the spray control program for illicit crops in Colombia. Using similar worst-case assumptions for exposure, several other pesticides used for coca production, including mancozeb, lambda cyhalothrin, endosulfan, diazinon, malathion, and chlorpyrifos, were up to 10- to 100-fold more toxic to frogs than the Glyphos-Cosmo-Flux mixture. Comparing hazard quotients based on application rates, several of these compounds demonstrated hazards 3-383 times that of formulated glyphosate. Secondary effects, particularly of insecticides, are also a concern, as these agents selectively target the primary food source of amphibians, which may indirectly impact growth and development. Although the potential chemical impacts by other pesticides are considerable, physical activities associated with coca production, particularly deforestation of primary forests for new coca plots, portend the greatest hazard to amphibian populations. The entire production cycle of cocaine has been linked to ecosystem degradation. The clearing of pristine forests for coca propagation in Colombia is well documented, and some of these regions coincide with those that contain exceptional amphibian biodiversity. This is particularly problematic as coca production encroaches more deeply into more remote areas of tropical rain forest. Transportation of disease, including the chitrid fungus, to these remote regions via human intrusion may also adversely affect amphibian populations. Therefore, the cumulative impacts of coca production, through habitat destruction, application of agrochemicals, and potential transmission of disease, are judged to pose greater risks to amphibian populations in coca-growing regions than the glyphosate spray control program. [ABSTRACT FROM AUTHOR]

The article presents an overview and a conclusion of the series of articles published in the 2009 issue of Journal of Toxicology and Environmental Health which address the issue on the risks of the use of glyphosate herbicide to human health and environment. The issues on the effect of spray conditions on droplet size and the spray drift potentiality was addressed. Amphibian susceptibility to the herbicide, efficacy of other glyphosate formulations on coca, and an inventory on the amphibian diversity in Colombia were conducted to determine the environmental effects of the glyphosate. Studies linking the herbicide use to the pregnancy of women and DNA damage were also done to determine the effects on humans. A conclusion on the negligible risks of glyphosate was noted.

Cholinesterase-inhibiting pesticides are applied throughout Australia to control agricultural pests. Blood plasma cholinesterase (ChE) activity is a sensitive indicator of exposure to organophosphorus insecticides in vertebrates. To aid biomonitoring and provide reference data for wildlife pesticide-risk assessment, plasma acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities were characterised in nine species of native bird: King Quails (Excalfactoria chinensis), Budgerigars (Melopsittacus undulatus), White-plumed Honeyeaters (Lichenostomas penicillatus), Yellow-throated Miners (Manorina flavigula), Willie Wagtails (Rhipidura leucophrys), Australian Reed-Warblers (Acrocephalus australis), Brown Songlarks (Cincloramphus cruralis), Double-barred Finches (Taeniopygia bichenovii) and Australasian Pipits (Anthus novaeseelandiae). Plasma ChE activities in all species were within the range of most other avian species and all but one contained AChE and BChE; no AChE was present in King Quail, which has not previously been reported for any species. The lowest detectable plasma AChE activity was 0.10μmolmin-1mL-1in Budgerigars and the highest was 0.86μmolmin-1mL-1in Australian Reed-Warblers. BChE in the plasma ranged from 0.37μmolmin-1mL-1in Double-barred Finches to 0.90μmolmin-1mL-1in White-plumed Honeyeaters and Australian Reed-Warblers. The lowest proportion of AChE was found in Budgerigars (12.8%) and highest in Willie Wagtails (67.8%). No differences were detected in ChE activity at any time of day in Budgerigars and Zebra Finches (Taeniopygia guttata), although there was a significant difference in all ChE activity between seasons in Zebra Finches. [ABSTRACT FROM AUTHOR]

A 28-d zooplankton community level study with Fenpyroximate was performed in indoor microcosms of 1 m3 volume including water and sediment from natural sources. The microcosms were treated by simulating spray-drift of the formulated product. The nominal concentrations (0.1, 0.32, 0.56, 1.0, 3.2, and 10 μ g/L) were confirmed by chemical analysis of the application solutions. At a water depth of 30 cm, the peak concentrations were measured after 24 h. The most sensitive taxa were cyclopoid copepods with a clear reduction of abundance at 1.0 μ g/L and a water depth of 15-45 cm. The very fast recovery at that concentration within one day indicates that the decrease in abundance was caused by flight (behavioral) reactions followed by re-migration into the sampled part of the water column. At 3.2 μ g/L recovery took 28 days. For cladocerans, a similar but weaker response was observed at the next dose level. Active avoidance of chemical stress should be taken into account when predicting effects in the field or interpreting post application monitoring results. In micro- or mesocosm studies, zooplankton sampling strategies should be adjusted to include avoidance behavior. [ABSTRACT FROM AUTHOR]

Plant protection products with active micro-organisms are allegedly less hazardous to the environment and wildlife than synthetic chemical pesticides. Nevertheless, they need a proper pre-marketing environmental safety evaluation because of their potential toxicity and pathogenicity. Scientific and technical guidance on such a safety evaluation for regulatory purposes is scarce. Therefore, a risk decision tree is proposed to provide such guidance and to discern the acceptable from the unacceptable environmental risks. The decision tree is based on the risk criteria of the European Union. It takes integrally into account the characterisation, identification and efficacy and also emission, exposure, environmental effects and, finally, the environmental risk assessment. Case by case expert judgement remains necessary in view of limited knowledge of microbial ecology, limited experience with regulatory test protocols and taxonomic difficulties in relation to the indigenousness of active micro-organisms. The decision tree offers regulatory guidance on the environmental safety evaluation of microbial plant protection products. [ABSTRACT FROM AUTHOR]

In recent years, there has been escalating concern over the possible association between exposure to pesticides and adverse human health effects by a number of non-governmental organizations, professional and public interest groups. Recognizing the need to document the scientific basis of these concerns as a foundation for initiating a research theme devoted to linkages between exposures to pesticides and human health effects, the Canadian Institutes of Health Research (CIHR) requested a summary of recent research trends that address these linkages. Experts across Canada in the field of pesticide regulation and research were invited to participate in the review. The review summarizes the limitations of past and current studies related to pesticides and human health effects research and makes suggestions for future research priorities and proposed study designs that will improve the assessment of pesticide exposure, the associated health risks, and improved methodology for regulatory decision making. [ABSTRACT FROM AUTHOR]

Subacute studies of profenofos on mosquito fish, Gambusia affinis , were carried out for 20 days to assess the locomotor behavior and structural integrity of gill in relation to bioaccumulation and targeted enzyme acetylcholinesterase (AChE; EC 3.1.1.7). The sublethal concentration of 0.13 mg/L (1/5 of LC 50 ) altered locomotor behavior such as distance traveled and swimming speed in exposed fish. This could be due to inhibition in the activity of acetylcholinesterase and deformities in the primary and secondary lamella of gill. The bioaccumulation values indicated that the accumulation of profenofos was highest in viscera followed by head and body. The average bioconcentration factor values are 254.83, 6.18, and 2.52 μg/g for viscera, head, and body. The findings revealed that profenofos is highly toxic even at sublethal concentrations to the mosquito fish, Gambusia affinis . [ABSTRACT FROM AUTHOR]

Regulatory agencies have used laboratory toxicity tests for decades to assess potential risks of pesticide use to wildlife, but questions remain about the ecological significance of test results. Population models may provide a valuable tool for projecting the consequences of pesticide use if information exists on the relationship between exposure and effects on survival and fecundity rates. We review issues of using avian reproduction test results for estimating changes in fecundity rates of wild birds. The avian reproduction test originated from studies focused on eggshell quality and embryotoxic effects of bioaccumulating, organochlorine pesticides. Current pesticides exhibit other potential reproductive effects that are not measured or that are poorly characterized. Because several experimental design features of the laboratory test may lead to overestimation or underestimation of the magnitude of risk of a particular pesticide to wild birds, determination of the magnitude of effects on fecundity cannot be based solely on the results of standardized laboratory tests. Quantifying the overall impact of pesticides on avian fecundity rates for use in population modeling will require additional information from modified laboratory tests that address specific questions, field monitoring or experimental field studies, and simulation models of avian productivity. [ABSTRACT FROM AUTHOR]

This study was undertaken to demonstrate the toxicity of two pesticides, chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate) and 2,4-D (Dichlorophenoxyacetic acid) to tench (Tinca tinca Linnaeus). Pathological samples of damaged tench kidney showing lesions were taken for statistical analysis in order to quantify different parameters. Analysis revealed differences in the action and/or action time of the two pesticides. These differences were more acute in the case of 2,4-D thereby indicating a greater toxicity. These differences, expressed by mathematical formulae of numerical variables, would enable, a priori, the identification of the responsible pesticide and the time of acting in new natural cases of poisonings with these substances. [ABSTRACT FROM AUTHOR]

In the red-eared slider turtle, pesticides can alter expected sex outcomes, a major step in the inferred pathway of sex determination, and hatchling steroid physiology. Changes such as these can profoundly affect an organism's fitness. Other potential markers for effects on fitness include hatchling mass, hatchling use of maternal stores (residual yolk), and especially early hatchling growth rates. In the current study, red-eared slider turtles were exposed during embryogenesis to one of three compounds—chlordane, trans -Nonachlor, or p,p′-DDE—all of which affect sex determination in this species. Turtles were weighed at hatching, after a 28-d fasting period, and after 14 d of ad libitum feeding. All three compounds had some population-wide effects on changes in mass from time point to time point when compared to controls. From hatching to the end of the 28-d fast, turtles exposed in the egg to the mid-range doses of trans -Nonachlor and of p,p′-DDE lost mass and underwent a change in mass significantly different from controls. Additionally, turtles exposed to the two higher doses of trans -Nonachlor and the mid-range dose of chlordane grew significantly more than controls after 14 d of ad libitum feeding. These results point to a role for pesticides in endocrine disruption that extends beyond sex determination and sex development. [ABSTRACT FROM AUTHOR]

This paper looks at the environmental disruption caused by the Medfly eradication efforts of California in the 1980s. The produce-destroying Medfly was detected in Santa Clara County in June 1980. Aerial malathion spraying in Northern California began in July 1981 and was completed in September 1982, when the Medfly was declared eradicated from California. According to U.S. Department of Agriculture's environmental assessment of the eradication, sprays used in the program would not significantly affect non-target insect populations. The apparent pest outbreaks occurred because some natural enemies are more susceptible to aerial malathion-bait spray than are the pests they control. Even at low concentrations malathion-bait spray can be lethal to Encyrtus saliens, another parasitoid useful in controlling ice plant scale. Although most Medfly spraying was in urban areas, agricultural biological control projects were also disrupted. A yearly four billion dollar worth of California crops is dependent on bee pollination. Hives in the spray area experienced significant increases in bee mortality. Malathion is highly toxic to aquatic organisms. Fish kills from direct aerial spraying of natural surface waters occurred in San Tomas Aquino and Stevens creeks. INSET: Eradication or Biological Control?.

Pesticides used in Egypt are of different types such as organochlorine, organophosphorus, carbamates, ureas, anilides and pyrethroid. The four general categories of these pesticides are insecticides, fungicides, herbicides and bactericides. Organophosphorus insecticides are of great significance in pest control and increasingly used instead of organochlorine insecticides. Organophosphorus insecticides represent more than 80% of total insecticides used during 1995. Fungicides account for 65.5% of pesticides used in Egypt during the period 1994-95 and agricultural use constitutes the majority of applications. Herbicides account for less than 4% of the pesticides used during 1995 in Egypt. The residue levels of some organochlorine insecticides (OCIs) and polychlorinated biphenyls (PCBs) in water, sediment and fish samples collected from the River Nile, lakes, drains and irrigation canals were determined. The highest concentration of OCI was found in samples collected from site located at north of Aswan (2.2 mug/l). Generally, the levels of OCI in River Nile water are still within safety margins, compared to the permissible limits for drinking waters. Also, the results demonstrated that fish samples from the River Nile and main lakes are contaminated with low levels of OCI and PCBs and there is no public health risk from fish consumption. [ABSTRACT FROM AUTHOR]

A key new risk to our pollinators has been identified as exposure to neonicotinoid insecticides. These discoveries have refuelled the debate over whether or not the neonicotinoid insecticides should be banned and conflicting evidence is used in this battle. However, the issue is not black or white, but gray. It is not an issue of whether the neonicotinoids are toxic to insects or not. Clearly, all insecticides were designed and optimized for this attribute. The real question is, or at least should be, which insecticide is the safest for use for a particular need. [ABSTRACT FROM AUTHOR]

The section of "Mothproofing" focuses on the environmental aspects of mothproofing formulations. Synthetic-pyrethroid mothproofing formulations for wool has a potential risk to aquatic life. These insecticides are reported to be highly toxic to fish and aquatic invertebrates. Pyrethroids coupled with their low mammalian toxicity has generated much interest in their use for pest control because of its very high insecticidal activity. Research on permethrin shows that it is useful for the industrial treatment of wool.