In EIA terminology, what are secondary data?

• A. New field measurements
• B. Laboratory experiments
• C. Existing literature or government records reviewed to establish an environmental baseline
• D. Public surveys

Answer: (C)

In EIA, data are categorized by how they are obtained. Secondary data are information that already exists and was collected for purposes other than the current assessment, which you review to establish environmental baseline conditions without conducting new measurements. This includes sources like existing literature, government records, historical monitoring reports, and compiled datasets. They help provide context, save time, and fill gaps, but you must evaluate their relevance and quality before using them. The other options involve collecting new information directly for the study—new field measurements or lab experiments—or data gathered specifically for the project through surveys—so they are not secondary data.