CHEMICALS, TOXICITY & HEALTH

Transcription

1 CHEMICALS, TOXICITY & HEALTH Reetu Aggarwal Assistant Professor, Department of English, S.D.College, Barnala (India) ABSTRACT Toxic substances are those substances (pure or mixture) which may be harmful to the environment as well as to human health if swallowed, inhaled or entered through skin. Even some natural substances for example plants like poinsettias are toxic in nature and even some wild mushrooms and berries are found to be poisonous. Some man made productsin our homes which include furniture polish, drain cleaners, paints, detergents, air fresheners, household bleach and many others are also toxic in nature. For thousands of years, man was dependent on fresh food, fruits, grains and vegetables. But nowadays, with advance technology, a majority of food we buy from market contains chemical preservatives, additives and artificial sweeteners that are harmful for our health. These chemicals can enter into our body through several routes namely inhalation, ingestion, injection and contact with skin and eyes. These chemicals can be dangerous to kidneys, heart, brain, liver, eyes, lungs and several other vital organs. Not only this, but many other chemicals can cause other problems like skin irritation, nausea, vomiting, skin burns and nervous system breakdown. Exposure to pesticides, heavy metals and many other harmful chemicals at working places may lead to various cancers. The present review aims at gathering information about some toxic chemicals and their ill effects on health. Although to meet global needs a substantial use of chemicals is necessary, still a lot of efforts have to be done to ensure the environmentally sound management of these chemicals. I INTRODUCTION Toxicity is the extent or degree to which a substance can damage an organism, an animal or a plant. There are different terms that are used to specify the substructure of the organism which is affected such as cytotoxicity for cell and hepatotoxicity for liver. Toxicity of a substance is dose dependent, even snake venom, a highly toxic material, may not exhibit its toxic effects if swallowed in small dose. The nature of toxicity is quite different from hazard. It is the inherent property of the material which can cause unwanted effects on biological system whereas hazard is the probability that a substance can show its toxic effects. Therefore, a toxic substance may not be hazardous and can be used safely if handled with caution and on the other hand,the same toxic chemicals can be hazardous if not handled properly. RISK =TOXICITY*EXPOSURE (1) 22 P a g e

2 Health risk of a substance is a function of exposure and toxicity. A toxic material is a substance that may cause harm to an individual. II TOXIC MATERIALS- CLASSIFICATION According to one system, toxicants or toxic materials can be classified into three broad classes 1. Biological Toxicants: These include various microorganisms like Bacteria and Viruses that spread diseases. 2. Physical Toxicants:physical toxicants are the substances that distract biological processes due to their physical nature. For a substance to be physical toxicant, it is not necessary for it to be poisonous. Even water if consumed in high doses can be physical toxicant as it will reduce the concentration of vital ions. Asphyxiategases, though are not toxic in nature but still can be physical toxicant. 2.1 Chemical Toxicants Chemical toxicants include a number of organic compounds like methyl alcohol, methylene chloride, Benzene, Formaldehyde, Chloroform, many medicines in high concentration and inorganic substances like ammonia, hydrogen peroxide, sodium hypochlorite, ethylene glycol, metals like Mercury, Arsenic, and Lead etc. III ROUTES OF ENTRY A toxic material can enter into our body through different ways which are called roots of entry or roots of exposure. These roots of exposure can be inhalation, ingestion, injection& contact with skin or eyes. 1. Inhalation From respiratory track, many toxic gases, vapors of volatile liquids, sprays & solid dust particals enter into circulatory system via membrane from where the distribution is faster. These materials cause serious damage to the cells and tissues. 2. Ingestion Some substances,after enteringthrough mouth,pass into gastrointestinal tract that include mouth, oesophagus, stomach, small intestine & large intestine. After passing into gastrointestinal tract, they are absorbed into blood which causes damage to various body parts. 3. Injection Though injections are not common route of exposure, still,syringes used for handling various chemicals, sharp objects like glass and contaminated blades can also expose us to chemical toxicants. 4. Contact with Skin or Eyes 23 P a g e

3 Undoubtedly, it is a frequent route of exposure in the labs. While working in the labs various kinds of skin allergies, irritation & skin burns, occur when many chemicals enter the skin. Our eyes can also be affected by many other chemicals by direct exposure at the working place. Here is a list of some toxic chemicals we find around us at our homes & at our working places along with their effects on health. IV COMMON TOXICANTS 1. Air Fresheners Contain a number of toxic chemicals. These contain Formaldehyde which irritates lungs & is carcinogenic &Pdichlorobenzene causes irritation to eyes. 2. Antifreeze Contains ethylene glycol & if swallowed can cause damage to brain, heart & kidneys & also cause dizziness. 3. Oven Cleaner May contain Sodium hydroxide or potassium Hydroxide that are very corrosive bases.if inhaled, can cause skin burns & can be fatal if swallowed. 4. Drain Cleaners Contains Sodium Hydroxide or Sulphuric acid. Both can cause serious skin burns & may cause blindness, if enter eyes through splash. 5. Mothballs May contain either Naphthalene or p-dichlorobenzene. They can cause headache, dizziness, skin & eye irritation & may also damage liver in case of prolonged exposure. 6. Laundry Detergents May cause nausea, vomiting & can also irritate skin &eyes. 7. Talc Talc is mainly used to absorb sweat, moisture& provide a hint of sparkle in eye shadows, blush, and baby powder. It is known to act as carcinogenic & is directly linked to ovarian cancer. 8. Motor Oil Contains a number of heavy metals. It can cause nerve & kidney damage. Various hydrocarbons present in it may cause cancer. 9. Car Batteries The main component present in these batteries is sulphuric acid.if splashes results in skin burns & blindness. Secondly, lead present in the batteries is also toxic in nature. 10. Paints 24 P a g e

4 Different organic solvents used in various paints can irritate eyes & skin. If inhaled, paint fumes results in headache &nausea. 11. All-purpose cleaners Ammonia present in these cleaners, if inhaled, can irritate eyes, skin rashes & skin burns. 12. Bleach It commonly contains sodium hypochlorite that is harmful to skin & lining of mouth, nose& throat. Its fumes irritates eyes & respiratory tract. 13. Dish Washer Detergents These are corrosive to skin & irritates mouth, throat& gastrointestinal tract. 14. Anti-BacterialCleaners They contain a number of toxic components. Cresol present can be very corrosive to tissues & it can damage lungs, liver, pancreas, kidneys & spleen.phenol can affect circulatory system & central nervous system. It can also cause cancer.pine Oil present in some antibacterial cleaners may cause irritation to eyes & lining of mouth, nose& throat. 15. Toilet bowl cleaners It has oxalic acid as one of the major component that can damage kidney, liver, cancorrode mouth, stomach,and irritates eyes & respiratory tract.sodium bisulphate present in it forms Sulphuric acid that along with hydrochloric acid already present are extremely corrosive to skin.another toxic chemical present in these cleaners is phenol. 14. Body Washes, Shaving Creams,Shampoos,Soaps &Deodorants All these personal care products contain number of chemicals that are very harmful to our health. They may contain formaldehyde as disinfectant & preservative, diethanol ammine (DEA) as contaminant, Triclosan as antibacterial.formaldehyde is linked with multiple health problems as eye & skin irritation, immune system damage, triggering asthma, genetic damage & even cancer.dea is also a known Carcinogen.Triclosan is found to be absorbed through skin &secreted in breast milk. It may also cause cancer. 15. Nail Polish & Nail Strengtheners Hazardous chemicals like butylacetate & toluene are found in nail polishes to strengthen the nails & to give a glossy touch. Butyal acetate vapours may cause drowsiness & dizziness. If exposedfor long time, skin may become dry & get cracks. Toluene is also toxic in nature. It may damage reproductive system & is also carcinogenic. 16. Food Packaging Material Poly vineyal chloride (PVC) is used in making food packaging material which is a known carcinogen & is linked with breast & liver cancer. 17. Plastic Food containers 25 P a g e

5 Bisphenol A(BPA) is widely used to make hard, clearpolycarbonate plastics for baby bottles, sippingcups, water bottles & food containers.trace amount of BPA leach from polycarbonate containers into food & liqiuids.expousre to BPA can affect reproductive development, early puberty in girls. It is also known to be endocrine disrupter. 18. Pillows, Mattresses& Carpets Polybrominated diphenyl ethers (PBDE) are commonly found in couches, pillows, mattresses& carpet padding. They are not chemically bound to the foam & hence released easily in dust with passage of time. Exposure to even small amount of PBDE can affect learning, memory, and hearing& can damage reproductive system. 19. Rat Poisons Can cause internal bleeding if swallowed. V. CONCLUSION No doubt a substantial use of chemicals is necessary to meet social & economic needs of the society but the excessive use has led to damage of human health &geneticstructure.the long term effects of pollution has brought significant changes in earth s atmosphere & climate.a number national & international bodies are working hard in these directions but a lot has yet to be done to ensure enviournmentaly sound management of toxic & hazardous chemicals to improve quality of human life. REFERENCES 1.Godman, Alexandra, Household Hazards:Potetial Hazardous of House Cleaning Products 2. Renner, Rebecca From Triclosan to Dioxin Environmental Science &Technology 36 (11) (June 1)230A. 3. Steinemall, A Davis,D Ribeiro & L Wallace Fragranced Consumer Products: Chemicals emitted, IngredientsUnlisted Environmental Impact Assessment Review 31(3)(April): Chiras. (2001) EnvironmentalScience: Creating a Sustainable Future (6 th ed.)sudbury, MA.Jones& Bartlett. 26 P a g e