Carcinogenic agents are substances, including chemicals, radiation, and some viruses, that promote cancer formation by damaging DNA or disrupting metabolic processes. The latency period varies from short to decades, with several factors influencing whether exposure leads to cancer. Various classifications categorize carcinogens, highlighting their sources, such as environmental radiation and lifestyle factors, and emphasizing the importance of precautions to minimize exposure.

1. CARCINOGENIC AGENTS
Dr. V. MAGENDIRA MANI
Assistant Professor
Department of Biochemistry
Islamiah College (Autonomous), Vaniyambadi

2. A carcinogenic agents or carcinogen is any substances,
chemicals, medical or environmental radiation, some
viruses, lifestyle factors, and even some medications
that promotes carcinogenesis, the formation of cancer.
This may be due to the ability to damage the genome or to
the disruption of cellular metabolic processes

3. A carcinogen may directly damage the DNA in cells
(cause mutations), which in turn leads to a
disruption in the normal process of growth and cell
division of cells.

4. Latency Period
The latency period is the time between exposure to a
carcinogen and the time a cancer develops.
The latency period can be very short, such as exposures to
radiation in a nuclear disaster, or instead, many decades,
depending upon the particular carcinogen.
For substances with a long latency period, it may take
several decades before they are recognized as being

5. Carcinogens do not cause cancer in everyone who is
exposed; the ability of a carcinogen to cause cancer
depends on many factors, including the amount of
exposure, the length of exposure, the health of the
individual, and other factors in the person's life that
either raise or lower the risk of cancer.

6. 1. Chemicals/substances
2. Environmental
radiation
3. Medical radiation
4. Viruses
5. Some medications
6. Lifestyle factors
7. Pollution
Types of carcinogens include

7. Testing
it would be unethical to test substances for carcinogenicity in
humans,
Many studies to evaluate substances for carcinogenicity are
done on animals using high exposures
Prior to animal testing, many of these substances are first
looked at in cell cultures in a lab.

8. Classifications
The Environmental Protection Agency:
Group A: Carcinogenic to humans
Group B: Likely to be carcinogenic to humans
Group C: Suggestive evidence of being carcinogenic to humans
Group D: Inadequate information to assess carcinogenicity
Group E: Not likely to be carcinogenic to humans

9. Types of carcinogens
Chemicals/substances: Certain chemicals used the home
or workplace may be carcinogenic. For example, asbestos
in insulation can lead to lung cancer.
Environmental radiation: Ultraviolet radiation from the
sun is a well-known cause of skin cancer. Radon emitted
from the normal decay of uranium in the soil is leading
cause of lung cancer

10. Medical radiation: radiation used medically for
diagnostic tests and that used to treat cancer are
considered carcinogens.
For example, women who receive radiation therapy after
a mastectomy for breast cancer are at an increased risk of
developing lung cancer due to the carcinogenicity of
radiation.

11. Viruses: Viruses such as human papillomaviruses which
cause oral cancer and cervical cancer, and hepatitis C, which
can cause liver cancer are considered carcinogens. .
Some medications: Some chemotherapy drugs and
hormonal therapy can raise the risk of cancer. For example,
some of the chemotherapy drugs (such as Cytoxan) used to
treat women with early stage breast cancer may sometimes
lead to leukemia. Oral contraceptive use may increase the
risk of breast cancer in young women.

12. Lifestyle factors: Smoking and obesity are both
carcinogens in that they can be responsible for the
mutations which result in cancer.
Pollution: Both outdoor and indoor air may contain
pollutants that are carcinogenic.

13. We are exposed to carcinogens in our environment every day.
While it's likely there are substances we will learn are
carcinogenic in the future, we can take action today to lower
our exposure. Having an awareness, and recognizing that
there are likely carcinogens in our environment that haven't
yet been identified is a great start. Taking some simple safety
precautions, such as reading labels and wearing gloves if you
aren't familiar with a product you are working with.

14. Safety Precautions
❖ Read labels, and check out ingredients you are not
familiar with
❖ Follow directions for safe handling of chemicals at
home/work place
❖ wearing gloves, good ventilation, wearing a mask
❖ Follow recommended procedures when working with
chemicals
❖ Employers are required to provide Material Safety Data
Sheets