9Parasites
Some parasites in the environment, such as gut worms and hookworms, can be a source of allergies. They can exist in untreated drinking water and foods. When these organisms penetrate the body, they would release some substances into the gut and bloodstream, which can suppress your immune system and prevent the body from fighting against the parasites. The risk is higher in developing countries where hygiene and environment are not well controlled. Some effective ways to prevent this problem include cooking foods fully and purifying or chlorinating drinking water. [9]
