Understanding the source and chemical properties o

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Ammonia (NH3): in the construction of residential buildings, office buildings, hotels, restaurants, etc. in northern China, admixtures such as high alkali concrete expansion agent and concrete antifreeze containing urea are added to the concrete artificially to prevent the concrete from being frozen and cracked during winter construction, which greatly improves the construction progress. These admixtures containing a large amount of ammonia are reduced to ammonia in the wall with the changes of humidity, temperature and other environmental factors, and are slowly released from the wall, resulting in a large increase in the concentration of ammonia in the indoor air

at the same time, ammonia in indoor air can also come from indoor decoration materials, such as additives and brighteners used in furniture finishing, most of which use ammonia. Ammonia water is widely used in shampoo and beauty salons as a neutralizer in the process of perm

in addition, with the deepening of people's understanding of the destruction of the ozone layer by CFCs, CFCS have been banned as refrigerants all over the world. Ammonia, which has been used for a century and a half, has been reused. This is also a potential source of pollution

main hazards of ammonia in indoor environment

according to toxicological classification, ammonia belongs to low toxic compounds. Ammonia is a colorless gas. When ammonia in the ambient air reaches a certain concentration, it has a strong pungent smell. The olfactory threshold of human to ammonia is 0.5 ~ 1.0mg/m3. Ammonia is an alkaline substance, which can absorb water in tissues after entering the human body. It has high solubility, stimulates and corrodes the upper respiratory tract of the human body, and weakens the resistance of the human body to diseases. After entering the alveoli, ammonia is easy to combine with hemoglobin to destroy the oxygen transport function. Inhalation of a large amount of ammonia in a short period of time can lead to tears, sore throat, hoarseness, cough, dizziness, nausea and other symptoms. In severe cases, pulmonary edema or respiratory distress syndrome will occur, and respiratory tract irritation symptoms will occur at the same time. The American Association of manufacturing chemists stipulates that workers are allowed to work for 8 hours at ammonia concentrations below 100ppm




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