Final answer:
A hazard is anything that could potentially cause harm. While in road safety, it refers to a possible danger due to road users or conditions, environmental hazards pertain to contaminants and hazardous waste that harm humans or the environment.
Step-by-step explanation:
The definition of a hazard can be contextualized in various ways, depending on the field of discussion. In general terms, a hazard refers to anything that can potentially cause harm or pose a danger. When discussing hazards in relation to road safety, the correct definition is: A road user or road condition that could be a possible danger. This includes any situation, object, or condition that could lead to an accident or injury. It's important to not ignore such hazards, but rather be aware and take preventive measures to ensure safety.
Environmental hazards, on the other hand, often relate to contaminants and hazardous waste. A contaminant is a substance that may be harmful to humans or other forms of life when released into the environment. Hazardous waste is a type of waste that poses substantial or potential threats to public health or the environment and includes physical states such as gaseous, liquids, or solids. The Environmental Protection Agency (EPA) has developed management programs to regulate the recycling, treatment, storage, and disposal of such waste to prevent it from causing harm.
A specific type of environmental hazard is a biohazard, which is any biological material that could potentially make someone sick, such as disease-causing organisms found in used needles or bacteria grown in a laboratory.