Answer:

1.They can pose a threat to human health when they are inhaled, eaten or come in contact with skin. They can cause illness such as food poisoning, tetanus, respiratory infections or parasite infection.

2.

*organ damage

*weakening of the immune system.

*development of allergies or asthma.

*reproductive problems and birth defects.

*effects on the mental, intellectual or. physical development of children.

*cancer.

3.

*muscle strain,

*muscle imbalances

*and fatigue.