Definition

For years, scientists interested in the impact of human activities on the environment studied the way in which the environment's chemistry affected the health of the aquatic communities.

Questions included:

• Are there too many toxic chemicals?
• Is the pH in the right range?
• Are nutrient concentrations too high?
• Are there too many suspended solids?

As programs have been put into force that address chemical contamination in the environment, scientists have discovered the need to better understand the physical environment to make additional improvements to the ecosystem, especially for flowing water systems (rivers, streams, creeks). Physical factors in the river that affect the number and type of species present include:

• River size
• River flow
• River temperature
• Type of bottom (sand, rock, etc.)

All of these factors play a role in defining which organisms and how many are present in a river. Changes in the chemical or physical nature of a site can impact the fish, algae and invertebrates that live there. Ecological epidemiology, or eco-epidemiology, studies both the chemical and physical nature of the environment and how they both contribute to the health of the ecosystem.

P&G Beauty is helping to lead studies in this new science (see Eco-epidemiology publications & presentations listed below).

Applications and Results

P&G scientists use a variety of environmental models to understand the concentration of consumer products in the environment. Some of these computer models use Geographic Information Systems (GIS) to combine information on chemistry, ecology and the physical environment (e.g., river flow, river depth) to give them a clearer picture of the river. Ideally, they want to better understand if the ecosystem is responding to degradation in the physical or chemical environment. GIS software allows the user to study data at a specific site in a river.

For example, scientists can get river flow, chemistry and biology data all for the same location. The real power of GIS is that it is possible to do this analysis for hundreds or thousands of sites in the country P&G is interested in, and then overlay dozens of different types of data at each site to determine which factors control ecosystem health.

In a study of the entire state of Ohio, P&G researchers found that river size and local habitat (e.g., amount of "cover," which includes large rocks, logs and other places for fish to hide) were important for healthy communities. However, the percentage of effluent was consistently identified as the most prominent negative factor addressing impacts. Further, effluents in urban areas caused greater damage than effluents in rural areas.

Because consumer product ingredients are present at roughly the same concentration in urban and rural effluents, P&G scientists do not expect these ingredients to be responsible for the effect observed. However, much more research is needed and P&G's efforts are continuing.

Publications