International
Labour Organization
Your health and safety at work
YOUR BODY AT WORK
Exercise: Hazards and your health
| Question: | What is the reason that some hazardous substances only cause chronic health problems a long time after the exposure occurred? |
| Answer: | Because of latency periods. This is the period of time between the exposure and the first sign of disease. For example, many occupational cancers take 20 or 30 years to develop. |