Table 1 Major chemical carcinogens in humans

1

Aflatoxin - B1 [CAS:1162-65-8] & Aflatoxin - G1 [CAS:1165-39-5]: A group of toxic polynuclear (benzenoid type) metabolite molds produced chiefly by the fungus Aspergillus flavus; they are natural contaminants of a wide range of fruits, vegetables, cereal grains and improperly stored food. The B₁and G₁ strains are known carcinogens

2

Aromatic amines [CAS: 8007-70-3]: Benzidine-based and naphthyamine are procarcinogens examples that enter the body through the skin, lungs or intestine. The gradation of potency of the carcinogenic amines depends on their hydrophobicity, and on electronic (reactivity, propensity to be metabolically transformed) and steric properties

Azo dyes [CAS: 84812-61-3]: Any of a broad series of synthetic dyes that have –N = N- as a chromophore group. They are widely used in the food, pharmaceutical, cosmetic, textile and leather industries.

3

Asbestos [CAS: 1332-21-4]: A group of impure magnesium silicate minerals which occur in fibrous form. The various types serpentine, amphibole, amosite and crocidolite are highly toxic by inhalation of dust particles

4

Chemotherapeutic agents: Cytotoxic chemicals that are selectively destructive to malignant cells and tissues. They are classified into antimetabolites, anti-tumour, anthracyclines, topoisomerase inhibitors, plant alkaloids, and alkyting agents which are considered most important because they can add alkyl groups to the many electronegative groups under conditions which are present in some cells to modify DNA chemically. Examples of antineoplastic drugs:

Busulfan [CAS: 55-98-1]

Carboplatin [CAS: 41575-94-4]

Cisplatin [CAS: 9002-60-2]

Chlorambucil [CAS: 305-03-3]

Cyclophosphamide [CAS: 50-18-0]

Mechlorethamine [CAS: 51-75-2]

Oxaliplatin [CAS: 61825-94-3]

Thiotepa [CAS: 52-24-4]

5

Heavy metals

Arsenic ³²AS [CAS:7440-38-2]

Cadmium ⁴⁸Cd [CAS: 7440-43-9]

Chromium ²⁴Cr [CAS:7440-47-3]

Nickel ²⁸Ni [CAS:7440-02-0]

6

Hydrocarbons:

Soot [CAS: 98615-67-9]: An airborne powder made of amorphous carbon, whereas its gas phase contains polycyclic aromatic hydrocarbons.

Tobacco [CAS: 8037-19-2]: Cured leaves of the species Nicotiana tabacum that contains acids (citric, oxalic, formic), alkaloids (nicotine, anabasine, myosmine), carbohydrates (lignin, pentosans, starch, sucrose), as well as tannin, ammonia, glutamine, and micro amounts of zinc, iodine, copper, manganese and polonium ⁸⁴Po₂₁₀. Cigarette tar contains various aromatic ring compounds (especially benzo-[a] oyrene).

7

Vinyl chloride [CAS: 75-01-4]: CH₂ = CHCl,

It is a manufactured substance that is used to prepare polyvinyl chloride to make plastic products for use in food packaging, medical products, appliances, cars, toys, credit cards and rainwear, and leaches into air and water.