What does "accumulative" mean when discussing hazardous substances?

"Accumulative" when discussing hazardous substances refers to the concept of substances building up in the body over time. This occurs when the intake of a hazardous substance exceeds the body's ability to eliminate it, leading to increasing concentrations within bodily systems. Such accumulation can result in toxic effects, particularly if the exposure is chronic or prolonged. Understanding this concept is crucial for assessing the risks associated with exposure to hazardous substances, particularly in contexts such as occupational safety and environmental health, where individuals might be exposed repeatedly over time.

The other options describe different scenarios related to exposure or effects of hazardous substances. For example, rapid onset of symptoms corresponds to acute exposure, while "no effects observable" may indicate a scenario where the dosage is below harmful levels. Lastly, a single large exposure doesn't reflect the cumulative nature of hazardous substances, as it doesn't involve long-term buildup. Each of these aspects is important for understanding exposure impacts, but "accumulative" specifically denotes the gradual build-up characteristic of certain hazardous substances.