contamination

Everyday

1. The state of being made dirty, impure or harmful by something unwanted (water contamination). tree →
2. The act or process of contaminating something. tree →
3. (science) Unwanted material spoiling a sample or experiment. tree →

In the lessons

In health, science and news, contamination of water, food or air can make people ill; «cross-contamination» in kitchens spreads germs from raw to cooked food. In environment lessons, radioactive or chemical contamination can last a long time. It tells the reader there is something harmful where it shouldn't be.

Examples

• The water company found contamination in the reservoir. tree →
• Cross-contamination happens when raw meat touches cooked food. tree →
• Food labels warn about contamination with nuts. tree →
• Scientists wear gloves to avoid contamination. tree →
• Radioactive contamination stayed near Chernobyl for many years. tree →
• The beach was closed because of sewage contamination. tree →

Note

Uncountable: no «a», no plural. Verb: contaminate. «Cross-contamination» is an important food-safety word: allergens (like nuts) can also cross-contaminate food, which is dangerous for people with allergies.