Carcinogens, which induce mutations in DNA or chromosomes,
encompass a wide range of genotoxins including high-energy
radiation (e.g., UV light), chemical pollutants (e.g., tobacco smoke,
alcohol), and biological agents (e.g., oncogenic viruses).
Carcinogenesis arises from the accumulation of genetic damage,
with malignancies displaying heightened immunogenicity due to
mutational load. Carcinogens also provoke immune responses and
epigenetic changes, leading to genomic instability and cancer
progression. These agents are classified into chemicals, radiation
(ionizing and non-ionizing), and biological entities. Industrialization has saturated the environment with genotoxic
substances, increasing genetic disorders. Daily exposure to
genotoxic substances through manufacturing and consumption
exacerbates this issue. Key genotoxic chemicals include polycyclic
aromatic hydrocarbons, aromatic amines, nitrosamines, alkylating
agents, formaldehyde, arsenic, cadmium, benzene, and acrylamide.
Natural chemicals like benzo(a)pyrene and arsenic are also
genotoxic, with arsenic known for inducing apoptosis via reactive
oxygen species (ROS). Workers in industries such as pesticides,
sulphur, agrochemicals, coal mining, and gasoline are at high risk
due to occupational exposure. Understanding carcinogens is crucial
for assessing cancer risk and implementing prevention strategies.
Lifestyle factors like diet, smoking, alcohol, and medications also
contribute to genotoxicity and cancer risk. This chapter
underscores the significant impact of genotoxic substances on
human health.