CHEMICAL CARCINOGENS CHEMICAL CARCINOGENS. What is a Chemical Carcinogen? Any chemical compound which has been shown to cause cancer in humans or in.

CHEMICAL CARCINOGENSCHEMICAL CARCINOGENS

What is a Chemical Carcinogen?What is a Chemical Carcinogen?

Any chemical compound which has been shown to Any chemical compound which has been shown to cause cancer in humans or in animal studies.cause cancer in humans or in animal studies.

Hundreds of individual compounds have been Hundreds of individual compounds have been shown to induce cancers. Many thousands of shown to induce cancers. Many thousands of additional compounds are “suspect” carcinogens.additional compounds are “suspect” carcinogens.

Many are commonly used in laboratory Many are commonly used in laboratory procedures, manufacturing, and in industry.procedures, manufacturing, and in industry.

Most cause localized base changes in DNA Most cause localized base changes in DNA (exceptions are asbestos and diethylstilbestrol)(exceptions are asbestos and diethylstilbestrol)

Categories of Known Human Categories of Known Human CarcinogensCarcinogens

Chemicals (organic and inorganic)Chemicals (organic and inorganic) Agents encountered in occupational Agents encountered in occupational

exposure (e.g., benzene)exposure (e.g., benzene) Drug Therapies (particularly chemotherapy)Drug Therapies (particularly chemotherapy) Environmental agents (UV light, asbestos, Environmental agents (UV light, asbestos,

and tobacco)and tobacco)

Chemical CarcinogensChemical Carcinogens

Chemical Carcinogens ContinuedChemical Carcinogens Continued

Chemical Carcinogens ContinuedChemical Carcinogens Continued

How is Chemical Carcinogenicity How is Chemical Carcinogenicity Determined?Determined?

Epidemiological studies determine the relationship Epidemiological studies determine the relationship between a cancer suspect chemical and a human between a cancer suspect chemical and a human population over a long period of time.population over a long period of time.

Animal studies directly induce cancer in test animals using Animal studies directly induce cancer in test animals using a large sample of animals, usually of two or more species a large sample of animals, usually of two or more species with varying dose and time parameters. with varying dose and time parameters.

Experiments with animals are based on the premise that Experiments with animals are based on the premise that chemicals that produce cancer in animals will have similar chemicals that produce cancer in animals will have similar effects on human cells. Most known human carcinogens effects on human cells. Most known human carcinogens produce cancer in experimental animals.produce cancer in experimental animals.

Ames Test for CarcinogenicityAmes Test for Carcinogenicity

How do Carcinogens Enter the Body?How do Carcinogens Enter the Body?

Skin absorption. Skin absorption. Ingestion. Swallowing of a carcinogen.Ingestion. Swallowing of a carcinogen. Inhalation. Breathing gases, fumes, and Inhalation. Breathing gases, fumes, and

vapors is the most common form of vapors is the most common form of exposure.exposure.

What Organs do Carcinogens Most What Organs do Carcinogens Most Frequently Attack?Frequently Attack?

LungsLungs LiverLiver KidneyKidney Reproductive systemReproductive system SkinSkin Many other organs and tissuesMany other organs and tissues

What Factors Influence the Development of Cancer?What Factors Influence the Development of Cancer?

Dose - amount and duration of exposure. The lower the Dose - amount and duration of exposure. The lower the dose the least likely you are to develop cancer or related dose the least likely you are to develop cancer or related diseases.diseases.

Environmental or lifestyle factors:Environmental or lifestyle factors: Cigarette smoking (co-carcinogen)Cigarette smoking (co-carcinogen) Alcohol consumption (co-carcinogen)Alcohol consumption (co-carcinogen) Diet - high fat consumption, low fiberDiet - high fat consumption, low fiber Fitness levelFitness level Age, race, and genderAge, race, and gender Geographic location - industrial areas, UV lightGeographic location - industrial areas, UV light Inherited conditions (Xeroderma pigmentosum) and genetic Inherited conditions (Xeroderma pigmentosum) and genetic

makeup makeup

How Can One Reduce Their How Can One Reduce Their Exposure to Carcinogens?Exposure to Carcinogens?

Minimizing One’s Exposure to CarcinogensMinimizing One’s Exposure to Carcinogens

General room ventilation - 10 or more changes of air per General room ventilation - 10 or more changes of air per hour. Designed to reduce exposures below the permissible hour. Designed to reduce exposures below the permissible exposure limit. exposure limit.

Fume hoods.Fume hoods. Local ventilation - exhaust (sometimes supply) at the point Local ventilation - exhaust (sometimes supply) at the point

of use of a chemical. of use of a chemical. Biosafety cabinet--used for anticancer drugs, viruses.Biosafety cabinet--used for anticancer drugs, viruses. No bench top work in a laboratory setting.No bench top work in a laboratory setting.

Personal Protective EquipmentPersonal Protective Equipment

Respiratory protection - dust masks, respirators. Respiratory protection - dust masks, respirators. Respirators are primarily for use in non-lab areas, Respirators are primarily for use in non-lab areas, except for emergency response (spill cleanup)--except for emergency response (spill cleanup)--shops, floor stripping, construction operations shops, floor stripping, construction operations (painting).(painting).

Eye protection - safety glasses, splash goggles, Eye protection - safety glasses, splash goggles, and face shields.and face shields.

Hand protection - gloves and protective sleeves.Hand protection - gloves and protective sleeves. Protective clothing - lab coats.Protective clothing - lab coats.

Personal HygienePersonal Hygiene

No smoking, eating, drinking or application of cosmetics is No smoking, eating, drinking or application of cosmetics is permitted in areas where carcinogens are in use (or in any lab permitted in areas where carcinogens are in use (or in any lab area!). No mouth pipetting!area!). No mouth pipetting!

Wash hands and any exposed skin if potentially Wash hands and any exposed skin if potentially contaminated - face, neck, forearms, etc.contaminated - face, neck, forearms, etc.

No shorts or open-toed shoes.No shorts or open-toed shoes. Remove lab coat or other potentially contaminated protective Remove lab coat or other potentially contaminated protective

clothing before leaving the work area. Lab coats need to be clothing before leaving the work area. Lab coats need to be cleaned regularly.cleaned regularly.

Contaminated disposable clothing should be treated as Contaminated disposable clothing should be treated as hazardous waste.hazardous waste.

Labeling of ContainersLabeling of Containers

All containers of chemical carcinogens need All containers of chemical carcinogens need to have a warning label affixed to them. to have a warning label affixed to them.

“ “DANGER : Contains ___________DANGER : Contains ___________ CANCER CANCER

HAZARD”HAZARD”

Storage of CarcinogensStorage of Carcinogens

Carcinogens must be stored separately from Carcinogens must be stored separately from other materials. other materials.

Separated by shelving system or secondary Separated by shelving system or secondary containment.containment.

Storage areas must be labeled “Danger--Storage areas must be labeled “Danger--Carcinogens Stored Here.”Carcinogens Stored Here.”

Disposal of Carcinogen Waste MaterialsDisposal of Carcinogen Waste Materials

All contaminated substances (paper towels, All contaminated substances (paper towels, supplies, etc.) must be properly labeled and sent supplies, etc.) must be properly labeled and sent out for incineration as Regulated Medical Wasteout for incineration as Regulated Medical Waste

Carcinogens may never be disposed of in the Carcinogens may never be disposed of in the ordinary trash.ordinary trash.

Dry wastes must be autoclaved and shipped out as Dry wastes must be autoclaved and shipped out as regulated medical waste (“Chemotherapeutic regulated medical waste (“Chemotherapeutic Agents”).Agents”).

Ultimate Goals Ultimate Goals Determine the various mechanisms Determine the various mechanisms

by which known carcinogens act and by which known carcinogens act and to identify the function of specific to identify the function of specific

genes that confer increased genes that confer increased susceptibility, or which are the targets susceptibility, or which are the targets

of environmental carcinogens.of environmental carcinogens.