Introduction:
Chlorophenols are a group of chemicals that consist of hydrogen replaced by chlorines on phenol. There are five chlorophenols: mono-chlorophenols, dichlorophenols, trichlorophenols, tetrachlorophenol, and pentachlorophenol. Since the 1930s, chlorophenol has synthesized dyes, pesticides, pharmaceuticals, and intermediate-manufacturing agricultural chemicals. They are also used as a solvent, disinfectant, and antiseptic. Monochlorophenol, dichlorophenol, and trichlorophenol are precursors for producing chlorophenol products.
Chlorophenols enter the environment through various ways, such as pesticides, insecticides, and industrial wastes. They help increase agricultural and industrial productivity but also cause environmental and health problems when these products are disposed of. Public health problems may arise by forming harmful substances through thermal and chemical degradation of chlorophenol. The environmental degradation of large amounts of pesticides, such as chlorobenzenes and cyclohexanes.
Products are toxic when there is a transformation of chlorophenol due to the formation of electrophilic metabolites. These metabolites may bind and damage deoxyribonucleic acid (DNA). The production of these harmful chlorophenols and their derivatives leads to cancer, changes in histopathology, and acute toxicity. So, there is a need to control chlorophenol in the environment to avoid human health issues. Recommendations made by the European Union to control the emission of industrial discharge. They have set a target limit for maximum pesticide concentration to avoid harmful environmental and human health effects.
During the time of chemical release, use local exhaust ventilation. While working, it is essential to wear protective clothing. Post-hazard and warning information should be given in the working area as a part of education. Work practice should be done safely.
What Is Chlorophenol and Its Derivatives?
Chlorophenol has been used for various industrial and domestic needs but also causes environmental toxicity, damage to living organisms' DNA, oxidative stress, and cancer. Derivatives of chlorophenol are catechol, chlorocatechols, guaiacol, syringol, and chlor guaiacol. These derivatives have toxic properties such as cancerogenic, mutagenic, and cytotoxic activity.
What Is the Effect of Chlorophenol on Environmental Conditions?
Chlorophenols are used for industrial pulp bleaching with chlorine, water disinfection, or waste incineration. The use of chlorophenol for industrial purposes leads to the release of xenobiotics into the environment. The environment absorbs these, and chlorophenols are recalcitrant to biodegradation. Bioremediation tools are used to destroy biological degradation. There are two approaches to dealing with environmental contamination. The first approach is before using chlorophenol, and it is essential to prove the safety of the chemical and its byproducts. The second approach is chemical-causing toxicity; risk should be determined before using chemicals. The disadvantage of the second approach is clear scientific proof of toxicity. Chlorophenol and its derivatives used for industrial and domestic purposes have significant effects on the environment and human health. Since chlorine atoms replace hydrogen atoms, chlorophenol increases toxicity, which is cancerogenic, cytotoxic, and mutagenic. In living organisms, the period of bioaccumulation is also prolonged.
How Does Chlorophenol Cause DNA Damage in Living Organisms?
These chemicals are exposed to humans, releasing Pentachlorophenol and trichlorophenol in the blood serum. Both chlorophenols from blood serum enter into the cell and result in damage to DNA. Damage may be single-strand or double-strand breaks or DNA base oxidation.
Dichlorophenol shows teratogenic, hepatotoxic, neurotoxic, genotoxic, and cytotoxic effects. They are also immunosuppressive. Dichlorophenol and catechol in human erythrocytes increase carbonyl group content. In a fenton reaction, hydroxyl radical forms from hydrogen peroxide that is highly reactive. This conversion takes place through transition metals such as iron and copper. This formation of hydroxyl radicals takes place during oxidative DNA base damage. The primary repair of oxidative DNA base damage is by base excision repair. Base repair is by the Formamidopyrimidine-DNA glycosylase, which removes the specified bases. This forms an apyrimidinic site later cleaved by apyrimidinic lyase activity. This provides a gap in the DNA strand.
How Does Chlorophenol Cause Stress?
The use of chlorophenol enters the environment and then into the food. When it enters the body from food consumed, Pentachlorophenol causes liver carcinogenesis. This leads to oxidative stress and hepatocellular proliferation. This proliferation plays a role in the pathophysiological process of the liver. These chlorophenols also oxidize proteins and lipids. This, in turn, causes reactive oxygen species. There is also a decrease in glutathione hormone and a change in other anti-oxidative systems.
How Does Chlorophenol Cause Cancer?
The various epidemiological studies show a relationship between cancer and exposure to chlorophenols. Pentachlorophenol causing human cancer was classified by the International Agency for Research on Cancer. Chlorophenol can cause excesses of non-Hodgkin's lymphoma, multiple myeloma, soft tissue sarcoma, and nasopharyngeal carcinoma. Studies show clinical findings of lung cancer, sarcoma, and tumors. Individuals exposed to chlorophenol may develop cancer, which leads to the activation of cytochrome P450.
How Does It Affect Health After Exposure?
Health effects may be acute or chronic based on the route of exposure and dose. In acute health effects, contact with chlorophenol can burn the eyes and skin and cause headaches, dizziness, fatigue, coma, restlessness, etc. In chronic health effects, it damages the liver and kidneys. It can also cause cancer. Medical testing should be done if there are symptoms. Liver and kidney tests should be done to rule out any damage.
Conclusion:
The environmental threat caused by chlorophenol is due to industrial wastes and chlorophenol degradation. Chlorophenol is a harmful substance to human health. The amount of toxic effect depends on the dose of chlorophenol. The main route for the human population is through water and food. It also causes DNA damage, oxidative stress, and damage to the liver and kidney.
