Why is benzo a pyrene toxic?

Why is benzo a pyrene toxic?

Benzo[a]pyrene is a probable cancer-causing agent in humans. There is some evidence that it causes skin, lung, and bladder cancer in humans and in animals. If benzo(a)pyrene is on your skin when you are being exposed to sunlight or ultraviolet light, the risk of skin cancer is greater.

Is benzopyrene a carcinogen?

The substance with the formula C20H12 is one of the benzopyrenes, formed by a benzene ring fused to pyrene. Its diol epoxide metabolites (more commonly known as BPDE) react with and bind to DNA, resulting in mutations and eventually cancer. It is listed as a Group 1 carcinogen by the IARC.

In which compound benzo purple ring is present?


What is the source of benzopyrene?

A chemical that comes from certain substances when they are not burned completely. It is found in car exhaust, smoke from wood fires, tobacco, oil and gas products, charred or grilled foods, and other sources. It may also be found in water and soil.

Is benzopyrene a cigarette?

Cigarette smoke is a known source of exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs), especially benzo[a]pyrene (BaP).

How does benzo a pyrene cause mutations?

Abstract. Benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon, is the major cause of lung cancer. BaP forms covalent DNA adducts after metabolic activation and induces mutations.

Is pyrene a carcinogen?

The PAH prototype benzo[a]pyrene (B[a]P), an AhR ligand, exhibits a strong carcinogenic potential and it is classified as a carcinogen to humans by the International Agency for Research on Cancer (IARC).

How does benzo a pyrene damage DNA?

Within a lung cell, benzo[a]pyrene is converted to an epoxide. The epoxide reacts readily with guanine (G) positions of the DNA helix. If not corrected by the cell’s DNA repair mechanism, this guanine “adduct†is misread as a thymine by the DNA polymerase that copies chromosomes during replication.

Is benzopyrene a PAH?

Benzo[a]pyrene is the most well-studied PAH, a cancer-inducing substance for which toxicological data serve as quantitative benchmarks for the entire carcinogenic subgroup.

How much more is benzopyrene than tobacco?

Marijuana smoke contains about 50 percent more benzopyrene and about 75 percent more benzanthracene than cigarette smoke. So, how do all of these compounds affect your lungs? Well, it’s not necessarily the compounds themselves, but rather how the compounds are entering your body.

How does benzopyrene affect DNA?

Why is BaP carcinogenic?

After elution in the lung, BaP is metabolically activated to its electrophilic, carcinogenic from by a complex enzyme system whose activity is increased by prior exposure to air pollutants, cigarette smoke and certain drugs.

Is benzo a pyrene a PAH?

How much benzo a pyrene in a cigarette?

Cigarette smoking and environmental tobacco smoke are other sources of air exposure. Smoking one cigarette can yield an intake of 20–40 ng of benzo (a) pyrene [Phillips 1996; O’Neill et al. 1997]. Smoking one pack of unfiltered cigarettes per day yields 0.7 µg/day benzo(a)pyrene exposure.

What can you do about secondhand smoke?

There is no treatment for breathing in secondhand smoke. But there are ways to manage your exposure and treat conditions related to secondhand smoke inhalation. If you are regularly near secondhand smoke, you can reduce the danger by: Moving away from the smoker and finding a smoke-free place.


BaP belongs to the group of compounds known as polycyclic aromatic hydrocarbons (PAHs). PAHs are produced when organic material is burned incompletely or heated. Exhaust fumes from (diesel) vehicles and smoke from wood stoves contain PAHs, which are usually attached to dust particles.

Is benzopyrene a mutagen?

Introduction. Benzo[a]pyrene (B[a]P) is a potent mutagen/carcinogen, and an example of a polycyclic aromatic hydrocarbon (PAH), a class of substances produced by incomplete combustion, which are found ubiquitously in the environment (1–7).

Is benzo a pyrene in gasoline?

On average 36 percent of the benzo[a]pyrene in an automobile’s exhaust gas comes from the benzo[a]pyrene originally in the gasoline. Between 0.1 and 0.2 percent of the benzo[a]pyrene in the gasoline survives the combustion process and is recovered from the exhaust; 5 percent accumulates in the crankcase oil.

Is benzo (a) pyrene a carcinogen?

Tumorigenicity studies with diol-epoxides of benzo(a)pyrene which indicate that “(+/ -)”-trans- 7″beta”,8″alpha”-dihydroxy-9″alpha” 10″alpha”-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene is an ultimate carcinogen in newborn mice. Cancer Res 38: 354 -358.

What is the preamble to the toxicological review of benzo pyrene?

Toxicological Review of Benzo[a]pyrene xviii PREAMBLE TO IRIS TOXICOLOGICAL REVIEWS The Preamble summarizes the objectives and scope of the IRIS program, general principles and systematic review procedures used in developing IRIS assessments, and the overall development process and document structure. 1.

What is the concentration of benzo pyrene?

Benzo (a)pyrene was detected in air particulate matter from Augusta City, Italy during 10/1991 to 7/1992 at concentrations ranging from 1.14 in autumn to 6.75 ng/cu m in summer (10). Benzo (a)pyrene ranged in concentration from 0.037 to 0.55 ng/cu m, mean 0.21, in air samples collected in Aug to Sept 1989 from Brazzaville, Congo (11).

What is the epidemiology of benzo[a]pyrene immunotoxicity?

There are no human epidemiological studies that provide specific support for benzo[a]pyrene immunotoxicity; however, immunosuppression has been observed in studies following occupational exposure to PAH mixtures. However, these findings are limited by co-exposures to other constituents of PAH mixtures.