About Environmental Data
The tables below show the range of environmental data. The first table shows the types of data about the levels of chemicals. These provide enough information to evaluate or at least consider people's exposure to these chemicals. The second table are data that provide less information for any one chemical, but cover a larger number of chemicals that might be in the environment. These are better for setting priorities about what chemicals are more likely to be found in the environment, and which ones to collect more information about or to study further.
Useful for considering exposure to environmental chemicals
|Environmental Monitoring Data
||Measured levels of chemicals that people might be exposed to (e.g. in air, food or drinking water).
||Best type of environmental data for evaluating exposure.
||Monitors need to be located where people would be exposed and measuring for chemicals of concern. In many cases, the number of monitors and number of chemicals being measured are relatively small.
|Estimated (Modeled) Environmental Data
||Estimated concentrations of hazards in air, water or on land based computer models and other data.
||Pretty good for evaluating exposure. Possible to examine more chemicals and less costly than environmental monitoring data. Can provide additional data or fill in data gaps that may not be covered by monitoring data.
||These are estimates not actual data. The exposure estimates depend on the accuracy of the input data and models used. Data are often annual totals, so you don't know if a small amount of chemical is released throughout the year, or if a large amount is released at one time.
||Quantities of chemicals released by facilities or applicators.
||If combined with other data can be used to evaluate exposure. Provides data about many chemicals. Several years of data may be available and data may be updated routinely. Often used as input data to estimated or modeled data (above) to estimate exposure.
||The least valuable kind of data for estimating exposure because release data don't tell you how chemicals disperse or move through the environment. In many cases the quantities of chemicals being released are not precisely known. Data are often annual totals so you don't know if a small amount of chemical is released over the year, or if a large amount is released at one time.
Useful for setting priorities for future data gathering or studies
||Quantities of chemicals that facilities are allowed to release (e.g. facility permit data).
||Provides data about many chemicals. Good for examining potential effects of chemicals on the environment.
||Doesn't tell you what quantities of chemicals are actually released.
||Quantities of chemicals sold.
||Provides data about many chemicals. Good for examining potential effects on the environment.
||Doesn't provide information about quantities being released to the environment.
||Describes environmental events (e.g. spills, remediation programs, violations)
||Provides descriptive information about environmental events that may not otherwise be recorded.
||May not provide a lot of details about concentrations of chemicals released to the environment.
||Chemicals that are manufactured or in use.
||Provides data for many chemicals.
||Doesn't provide release information or information about the levels of chemicals in the environment.