INTRODUCTION
Eversince the evolution of man on earth,he has had a deep quest of knowledge which aimed at taming of Nature for the satisfaction of his deeply felt needs.When he found that the natural resources could not meet his requirements to the fullest,he diverted his efforts in making artificial products by imitating the nature ,for maximum utilisation.Thus these man made things became an inevitable part in human life which ultimately led to the progress of human civilisation .It is in this context that Science ,especially Chemistry has contributed a lot.As time passed by he began to realise that some of his most useful and essential products ,when used indiscriminately caused more destruction than their use! Chemical Hazards soon became the talk of the town!
Now let us see what exactly these Hazards are and how hazardous some of the most commonly used substances are!
Chemical hazards are caused mostly by careless or indiscriminate or prolonged or inefficient use of certain chemicals.These hazards were earlier very common in Big Factories and industrial centers.But as technology progressed Man found out various precaution methods and the cases of industrial hazards has significantly come down over the years.But still there are hazards happening, and most astonishing is the rate of household hazards that’s increasing.As the modern households are becoming more amd more sofisticated with latest technologies, rate of such disasters are also increasing.For eg.the most common indiscriminate use of Detergents which drastically replaced the ordinary Soap ,due to which the ecological balance is getting disrupted in a slow but alarming pace.
In this essay the focus is on certain chemicals carcinogens and the hazards posed by them.
As said earlier the use of detergents has really increased the risk of ecological imbalance.The improper and careless use of various household chemicals like bleaching powder,DDT,phenyl,certain medicines,aerosol sprays,Refridgerants containing CFCs etc cause hazards which have already been showcased and brought into attention of common man.But apart from these carcinogens there are several chemicals which we use daily ,but do not know the hazards.The Carcinogenisis of some of such compounds are discussed below.
CARCINOGENICITY OF ASBESTOS
There is sufficient evidence for the carcinogenicity of asbestos and the following forms of commercial asbestos in experimental animals: chrysotile, amosite , anthophyllite , and crocidolite .
PROPERTIES
Asbestos is the generic name given to a class of natural fibrous silicates that vary considerably in their physical and chemical properties. Chrysotile has an idealized chemical composition of Mg3(Si2O5)(OH)4
USE
Domestically used asbestos fibers are technically classified into seven quality categories or grades. Grades 1, 2, and 3 include the longer, maximum-strength fibers and are generally used in the production of textiles, electrical insulation, and pharmaceutical and beverage filters. Grades 4, 5, and 6 are medium-length fibers used in the production of asbestos-cement (A/C) pipe, A/C sheet, clutch facings, brake linings, asbestos paper, packaging, gaskets, and pipe coverings. Grade 7 includes short fibers generally used as a reinforcer in plastics, floor tiles, coatings and compounds, some papers, and roofing felts.
EXPOSURE AND HAZARDS
Asbestos fibers are released into the environment from the natural occurrence of asbestos in the earth and as a result of wear and deterioration of asbestos products. Asbestos minerals are emitted into the atmosphere and water systems from the mining and milling of asbestos ores.
The primary routes of potential human exposure to asbestos are dermal contact, inhalation, and ingestion.
When administered by inhalation, chrysotile, crocidolite, amosite, and anthophyllite induced mesotheliomas and lung carcinomas in rats and mesotheliomas after intrapleural administration. When filter material containing chrysotile was added to the diet, a statistically significant increase in the incidence of malignant tumors was observed in rats
There is sufficient evidence for the carcinogenicity of asbestos and all commercial forms of asbestos in humans also. Occupational exposure to chrysotile, amosite, anthophyllite, and mixtures containing crocidolite has resulted in a high incidence of lung carcinomas.Gastrointestinal cancers occurred at an increased incidence in groups occupationally exposed to crocidolite, amosite, chrysotile or mixed fibers containing crocidolite, although not all studies are consistent in this respect. An excess of laryngeal cancer has also been observed in some groups of exposed workers.Both cigarette smoking and occupational exposure to asbestos fibers increase lung cancer incidence independently.