The indoor air pollutants in the renovated new house mainly include formaldehyde, benzene series, TVOC, ammonia and so on.

Formaldehyde is a colorless irritating gas with strong smell, and its 35%~40% aqueous solution is commonly known as formalin.

Formaldehyde is a poison of protoplasm, which can combine with protein. After inhaling high concentration formaldehyde, severe irritation and edema of respiratory tract, stinging eyes, headache and bronchial asthma may occur. Direct contact with formaldehyde can cause dermatitis, pigmentation and necrosis. Regular inhalation of a small amount of formaldehyde can cause chronic poisoning, such as mucosal congestion, skin irritation, allergic dermatitis, nail keratinization and brittleness, nail bed fingertip pain and so on. Long-term inhalation by pregnant women may lead to malformation and even death of newborn babies. Long-term inhalation by men may lead to male sperm malformation, death and sexual dysfunction, and even lead to leukemia, pneumothorax and reproductive insufficiency. General symptoms include headache, fatigue, loss of appetite, palpitation, insomnia and weight. All kinds of man-made boards (particleboard, density board, fiberboard, plywood, etc. ) contains a lot of formaldehyde due to the use of urea-formaldehyde resin glue. Adhesives should be used in the production of new furniture and the decoration and laying of walls and floors. Where adhesives are used in large quantities, formaldehyde will always be released. In addition, some chemical fiber carpets, curtains, fabric sofas and paints also contain a certain amount of formaldehyde. Benzene is a colorless gas with a special fragrance. Toluene, xylene and benzene homologues are all products of coal tar fractionation or petroleum cracking. At present, toluene and xylene are often used as solvents or diluents for various adhesives, paints and waterproof materials in interior decoration, instead of pure benzene. Because benzene is volatile, flammable and explosive. Inhalation of toluene and xylene with high solubility in a short time may lead to central nervous system anesthesia, which is manifested as dizziness, headache, nausea, chest tightness, fatigue, confusion, and even coma and death due to respiratory and circulatory failure. If you are exposed to toluene and xylene with certain solubility for a long time, it will cause chronic poisoning and neurasthenia-like syndrome such as headache, insomnia, listlessness and memory loss. Benzene compounds have been identified as strong carcinogens by the World Health Organization. Benzene can be metabolized in liver and bone marrow, which is the place where red blood cells, white blood cells and platelets are produced. Therefore, when benzene enters the body, it can form metabolites with blood toxicity in hematopoietic tissue itself. Long-term exposure to benzene can cause bone marrow and genetic damage, and hemogram examination can find leukopenia and thrombocytopenia, pancytopenia and aplastic anemia, and even leukemia. The harm of benzene to the body can be summarized into three types: carcinogenesis, disability and teratogenesis.