B. Systemic effects

Systemic effects are problems caused inside the body once a hazardous agent has entered. Systemic effects can occur in the blood when the substance is absorbed into the bloodstream, and in the organs that either store the toxic material (such as the bones and the brain), neutralize it (such as the liver), or remove it from the body (such as the kidney and bladder).

A typical systemic effect in the blood is anaemia (a shortage of red blood cells) which can be caused by a number of chemicals, including: lead, beryllium, cadmium, mercury compounds and benzene. Benzene can damage the cells that form blood, leading to leukaemia.

The liver can be damaged by toxic substances because it tries to break down many of them once they have entered the body. Some chemicals known to damage the liver are: benzene, DDT, dioxane, phenol and trichloroethylene. Vinyl chloride monomer, used in the plastics industry, is known to cause a rare form of liver cancer.

The kidneys and bladder also can be affected by many toxic substances because they are major routes of exit out of the body.

Some hazardous substances that cause local and systemic effects