Rodent Sperm Analysis: A rationale for and path toward acceptance and use in ecological risk assessment.

The Rodent Sperm Analysis method was devised some two decades ago to advance ecological assessment science for mammals, one of two groups of terrestrial receptors routinely evaluated at chemically contaminated sites. In part, this method recognizes that sufficient time has elapsed at sites, such that a need to anticipate or predict impacts to ecological receptors is an obsolete task. The method therefore, recommends evaluating the very receptors that occupy sites for evidence today of their displaying compromised reproduction, a toxicological endpoint of great concern within the regulatory community.

Commentary: An open appeal to the EPA for Superfund ERA reform.

The ecological risk assessment guidance of virtually all federal and state agencies, private companies, and other interests can be traced to that of the essential design of the U.S. Environmental Protection Agency (EPA).

Ingestion of a Single 2.3 mm Lead Pellet by Laying Roller Pigeon Hens Reduces Egg Size and Adversely Affects F1 Generation Hatchlings.

Many aquatic and terrestrial avian species inadvertently ingest lead (Pb) in the form of spent or fragmented ammunition, mistaking it for food or grit. Previous studies in our laboratory have shown that ingestion of even a single 45-mg pellet can significantly increase blood-Pb levels and significantly inhibit the enzyme delta aminolevulinic-acid dehydratase (δ-ALAD) for a period of greater than 4 weeks. In the current study, proven breeder pairs of domestic Roller pigeons were housed in individual cages.

Validating mammalian resistance to stressor-mediated reproductive impact using rodent sperm analysis.

Small rodents from chemically and radiologically contaminated areas on the Savannah River Site, SC were evaluated for sensitive reproductive parameters in a dual purpose study. The primary intent was to observe if established reproductive thresholds-for effect could be exceeded in animals that, due to their restricted home ranges, are maximally exposed to local contamination. Secondarily, validation was sought for a principal element of the Rodent Sperm Analysis method that is used in support of ecological risk assessments for contaminated terrestrial properties.

Exposure Duration-Dependent Ovarian Recovery in Methoxychlor-Treated Mice.

The pesticide methoxychlor (MXC) is known to target ovarian antral follicles in the mouse. In previous in vivo studies, MXC administration for 20 days increased atresia, but did not affect female fertility immediately after dosing. Thus, we hypothesized that perhaps not enough time had elapsed between the onset of MXC-induced atresia and actual follicle loss to result in reduced fertility.

Where deer roam: chronic yet acute site exposures preclude ecological risk assessment.

Global positioning system (GPS) technology has made possible the detailed tracking of the spatial movements of wildlife. Using GPS tracking collars placed on female white-tailed deer (Odocoileus virginianus) over a protracted period, we illustrate that this species is spatially irrelevant for consideration in ecological risk assessments (ERAs) for commonly assessed contaminated sites. Specifically, deer movements do not allow for a sufficiency of chemical exposures to occur such that toxicological endpoints would be triggered.

Methoxychlor-induced ovarian follicle toxicity in mice: dose and exposure duration-dependent effects.

Background: Methoxychlor (MXC) is specifically known to target ovarian antral follicles, increasing atresia (death via apoptosis) in them. This is of concern because females are born with a finite pool of ovarian follicles. Only limited studies have explored the phenomenon of a reduced fertility threshold for effect based on the percentage of antral follicle atresia.

Correlational sperm motility analysis: wild rodent progressive sperm motility as a potentially improved reproduction-assessment parameter in mammals.

Progressive sperm motility, describing the directed or linear movement of sperm, is infrequently reported in reproductive studies conducted with rodents. This is a curious circumstance given that progressive motility can be easily reported with current computer-assisted sperm-analysis equipment, and because progressively motile sperm seemingly display a greater likelihood of fertilizing ova than do sperm that move in a random or undefined pattern. This study presents a comparison of the routinely reported total motility (i.

Testing the limits of Rodent Sperm Analysis: azoospermia in an otherwise healthy wild rodent population.

By comparing the sperm parameters of small rodents trapped at contaminated terrestrial sites and nearby habitat-matched noncontaminated locations, the patent-pending Rodent Sperm Analysis (RSA) method provides a direct health status appraisal for the maximally chemical-exposed mammalian ecological receptor in the wild. RSA outcomes have consistently allowed for as definitive determinations of receptor health as are possible at the present time, thereby streamlining the ecological risk assessment (ERA) process. Here, we describe the unanticipated discovery, at a contaminated US EPA Superfund National Priorities List site, of a population of Hispid cotton rats (Sigmodon hispidus), with a high percentage of adult males lacking sperm entirely (azoospermia).

Demonstrating ecological receptor health at contaminated sites with wild rodent sperm parameters.

Consistently at Superfund and other contaminated terrestrial sites, ecological receptors have been chemically exposed for multiple decades by the time risk assessments are conducted. Given that numerous generations of the receptors have lived through the contaminated site condition by the present day, a paradigm shift from risk assessment, where the potential for health effects are forecasted, to a direct, health status assessment scheme for the site-exposed receptor, would seem to be most appropriate. We applied the only such existing direct health status assessment method, Rodent Sperm Analysis (RSA), with small rodents trapped at contaminated sites and at matched noncontaminated reference locations.

Two simple algorithms for refining mammalian receptor selection in ecological risk assessments.

Although guidelines exist for selecting appropriate ecological receptors for risk assessments at contaminated sites, it can be demonstrated that many of the mammals commonly evaluated are spatially irrelevant. Terrestrial risk assessments could be simplified and made more efficient, though, if mammals that are initially considered were screened for their spatial relevance. This article presents 2 simple algorithms that each demonstrate that most mammalian receptors are not spatially relevant for the overwhelming majority of hazardous waste and other contaminated sites.

A critical assessment of the ecological risk assessment process: a review of misapplied concepts.

A frank assessment of present-day ecological risk assessments (ERA) for managed contaminated sites reveals that fundamental concepts regarding the receptors that are considered and the chemical exposures they experience are commonly misapplied. As a consequence, environmental managers are not being supplied with the information needed for proper decision making. The stepwise review of ecological risk issues provided here suggests that the ERA process needs I to be severely revamped.

Rodent sperm analysis in field-based ecological risk assessment: pilot study at Ravenna army ammunition plant, Ravenna, Ohio.

Ecological risk assessment (ERA) guidance recommends that field-truthing efforts proceed when modeled hazard quotients (HQs) suggest that toxicological effects are occurring to site receptors. To date, no field methods have been proposed by the regulatory community that can lead to definitive determinations of acceptable or unacceptable risk for birds and mammals, the two terrestrial classes of receptors that are commonly assessed using the HQ method. This paper describes rodent sperm analysis (RSA) as a viable method to be applied in the field at sites with historical contamination.