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In the current paper we describe the methodology and results of the Oswego study, in light of D.V. Cicchetti, A.S. Kaufman, and S.S. Sparrow's (this issue) criticisms regarding the validity of the human health/behavioral claims in the PCB literature. The Oswego project began as a replication of the Lake Michigan Maternal Infant Cohort study. Beyond replication of the Michigan findings, the study sought to extend results and conclusions through more comprehensive behavioral assessment, and improved confounder control and analytic methodology. Results over the past 5 years have demonstrated a convincing replication of the Michigan findings. The Michigan cohort reported findings relating Great Lakes fish consumption to performance impairments on the Neonatal Behavioral Assessment Scale (J. Jacobson, S. Jacobson, P. Schwartz, G. Fein, & J. Dowler, 1984). These findings were also found in the Oswego cohort (E. Lonky, J. Reihman, T. Darvill, J. Mather, & H. Daly, 1996), and the Oswego study extended the association to cord blood PCBS (P.W. Stewart, J. Reihman, E. Lonky, and T. Darvill, 2000). The Michigan cohort reported an association between prenatal PCB exposure and poorer performance on the Fagan Test of Infant Intelligence (S.W. Jacobson, G.G. Fein, J.L. Jacobson, P.M. Schwartz, & J.K. Dowler, 1985). The Oswego cohort found similar results (T. Darvill, E. Lonky, J. Reihman, P. Stewart, & J. Pagano, 2000). The Michigan Cohort reported an association between prenatal PCB exposure and performance impairments on the McCarthy Scales of Children's abilities (J. Jacobson & S. Jacobson, 1997). The Oswego study also found PCB-related impairments on the McCarthy Scales (P.W. Stewart, J. Reihman, E. Lonky, T. Darvill, & J. Pagano, 2003). The Oswego results used the same exposure metric in every paper, employed conservative statistical design and analysis, and controlled for more than 40 potentially confounding variables. Moreover, while PCBs were related to all the behavioral endpoints outlined above, alternative candidates for effect, including lead, HCB, Mirex, DDE, and MeHg were not. Taken together, these results support the hypothesis that prenatal PCB exposure results in statistically significant predictors of small, but measurable, deficits in cognitive development from infancy through early childhood. Cicchetti et al. argue that these results, generated by independent investigators, be dismissed because they reflect a combination of measurement error, Type I error, and residual confounding. The evidence Cicchetti et al. present in support of their position fails to explain the nearly identical pattern of associations observed in the Oswego and Michigan Cohorts. In light of this replication, the extensive assessment of potential confounders, the effective elimination of alternative contaminants, and the conservative statistical approach employed in the Oswego study, we find that Cicchetti et al.'s claims are not substantiated. (Contains 1 table.)

Riverine and palustrine wetland plant communities were examined in order to propose a multimetric plant index of biotic integrity. The objectives were to determine the structural and functional attributes of these wetland plant communities, calibrate reference conditions in assessing aquatic plant communities, provide methods for further development and testing of the index, and present a case study. The index is based on a rapid assessment method using the information collected from a species list and cover estimates. Sampling was done using a modified relevé sampling approach with a modified Braun-Blanquet Cover Abundance Scale Method for estimating percent cover. More than 20 characteristics of aquatic plant communities were evaluated and 12 metrics in five categories were developed. Structural metrics focused on community composition, key indicator species such as number of Carex and Potamogeton species, and guild type. Functional metrics included sensitivity and tolerance measures; percent emergent, pioneer, and obligate wetland species; and the number of weed species as a substitute metric. Abundance was estimated based on evenness of average cover densities. Individual condition was suggested as a measure of the lowest extremes of biotic integrity. Palustrine study sites ranged across a disturbance gradient from 'least-impacted' to 'poor'; riverine study sites ranged from high quality to some of the most degraded riverine sites in the Great Lakes region. Ninety-five species of aquatic vascular plants were found in 42 families. The most common families were Cyperaceae (15 species), Polygonaceae (9 species), and Juncaceae (6 species). Fourteen submergent, four floating, two woody and 75 emergent aquatic plant taxa were found. Five species were on the endangered, threatened, or rare list for the State of Indiana. Sites receiving the highest index scores included several of the a priori least-impacted sites while the lowest scores were located near-field to a large industrial landfill. The index will need to be further validated and tested but shows potential as a rapid index of biotic integrity using aquatic plant assemblages. [ABSTRACT FROM AUTHOR]