Final answer:
The true statement that worker risk from exposure to substances depends on the nature, potency, magnitude, and duration of exposure underlies the assessment of workplace hazards and environmental toxicology. Factors such as types of work activities, accidents involving carcinogens, and the chronic effects of long-term, low-level exposures must all be taken into account when evaluating health risks.
Step-by-step explanation:
The degree of worker risk from exposure to any substance indeed depends on the nature and potency of the toxic effects, as well as the magnitude and duration of exposure: a) True. The risk to workers can increase based on the types of work they perform, particularly if the work causes an increase in the exposure to harmful substances such as radiation or toxins like pesticides. For instance, agricultural workers who use pesticides extensively and those working in poorly ventilated environments are at higher risk for pesticide-related illnesses.
In the event of an industrial accident, the potential impact on a nearby community can be assessed by evaluating chemicals' residence times in the environment. Chemicals with longer residence times pose a greater risk of exposure over time. For example, if three equally harmful carcinogens are released into a river, the one with the longest residence time represents the greatest risk over the course of a week following the spill.
Toxic substances such as those found in tobacco smoke, including tar, carbon monoxide, and formaldehyde, pose significant health risks. Additionally, nicotine, present in tobacco, is highly addictive, and some consider it to have higher addiction potential than heroin, though this is still a subject of ongoing research.
An acute effect of a contaminant occurs quickly following exposure to a large dose, whereas a chronic effect emerges over a long period of time due to exposure to smaller amounts. Both effects are critical factors in assessing the risk to public health posed by contaminants, which vary based on the amount, duration, and type of exposure.