Probability surveys, conditional probability, and ecological risk assessment.

We show that probability-based environmental resource monitoring programs, such as the U.S. Environmental Protection Agency's (U.

Timing of increased autistic disorder cumulative incidence.

Autistic disorder (AD) is a severe neurodevelopmental disorder typically identified in early childhood. Both genetic and environmental factors are implicated in its etiology. The number of individuals identified as having autism has increased dramatically in recent years, but whether some proportion of this increase is real is unknown.

CProb: a computational tool for conducting conditional probability analysis.

Conditional probability is the probability of observing one event given that another event has occurred. In an environmental context, conditional probability helps to assess the association between an environmental contaminant (i.e.

Using field data and weight of evidence to develop water quality criteria.

In the United States, ambient aquatic life water quality criteria are derived using guidelines developed in 1985 that include a clear and consistent methodology using data from standard toxicity tests. The methodology from these guidelines has been successful, but a broader methodology is needed because some effects of pollutants do not lend themselves to conventional toxicity testing. Criterion assessment is proposed as that methodology.

Predicting estuarine sediment metal concentrations and inferred ecological conditions: an information theoretic approach.

Empirically derived relationships associating sediment metal concentrations with degraded ecological conditions provide important information to assess estuarine condition. Resources limit the number, magnitude, and frequency of monitoring activities to acquire these data. Models that use available information and simple statistical relationships to predict sediment metal concentrations could provide an important tool for environmental assessment.

Ecological condition of US Mid-Atlantic estuaries, 1997-1998.

The Mid-Atlantic Integrated Assessment (MAIA-Estuaries) evaluated ecological conditions in US Mid-Atlantic estuaries during the summers of 1997 and 1998. Over 800 probability-based stations were monitored in four main estuarine systems--Chesapeake Bay, the Delaware Estuary, Maryland and Virginian coastal bays, and the Albemarle-Pamlico Estuarine System. Twelve smaller estuaries within the four main systems were also assessed to establish variance at the local scale.

Developing and applying an index of environmental integrity for the US Mid-Atlantic region.

Environmental conditions in the Mid-Atlantic region of United States are presently being documented in a series of reports that use 'environmental report cards' to summarize the condition of individual natural resources (e.g. estuaries, streams, forests, and landscapes) over the entire region and within major subregions.

Incidence of stress in benthic communities along the U.S. Atlantic and Gulf of Mexico coasts within different ranges of sediment contamination from chemical mixtures.

Synoptic data on concentrations of sediment-associated chemical contaminants and benthic macroinfaunal community structure were collected from 1,389 stations in estuaries along the U.S. Atlantic and Gulf of Mexico coasts as part of the nationwide Environmental Monitoring and Assessment Program (EMAP).

An approach to integrated ecological assessment of resource condition: the Mid-Atlantic estuaries as a case study.

The complex and interconnected nature of ecological systems often makes it difficult to understand and prevent multiresource, multistressor problems. This article describes a process to assess ecological condition at regional scales. The article also describes how the approach was applied to the Mid-Atlantic estuaries, where it focused on characterizing the current state of the environment rather than on predicting future effects from humans.

Landscape metrics and estuarine sediment contamination in the mid-Atlantic and southern New England regions.

In a previously published study, quantitative relationships were developed between landscape metrics and sediment contamination for 25 small estuarine systems within Chesapeake Bay. These analyses have been extended to include 75 small estuarine systems across the mid-Atlantic and southern New England regions of the USA. Because of the different characteristics and dynamics of the estuaries across these regions, adjustment for differing hydrology, sediment characteristics, and sediment origins were included in the analysis.