Toxic environmental substances and cancer

Without statistics, it is easy to see that cancer patients are getting more and more in our country. Most hospitals have opened a cancer department, but are still overloaded when 2-3 patients share a bed.

Through research, scientists have come to the conclusion that the pollution environment, pollutants when exceeding the permitted level are the pathogenic toxins, including cancer.

In fact, cancer and cancer-causing toxins for humans have been studied for a long time. However, people only focus on one aspect of the ' medical toxicology ' problem, but forget about the ' environmental toxicology '. Indeed, in recent years, the abuse of chemicals in life is increasing, including: preservatives in food, plant protection drugs (herbicides, insecticides, kill mushroom…).

Patient with leukemia treated at Blood Transfusion Hospital - Ho Chi Minh City's happy blood in the autumn 2008 at the hospital (Photo: To Oanh)

People must always breathe toxic air including cigarette smoke, chlorine vapor, mercury vapor, metal dust, organic chemicals contaminated with organic chemicals, grease, alcohol and regular contact with products. extra in the process of manufacturing, processing food as well as waste generated by industries. Here we would like to mention the most common and topical cancer-causing environmental toxins in our country:

* Dioxin poisoning : It is an extremely toxic type present in most of the component environment, but is less absorbed into water, exists a lot and long in soil and sediment (sometimes up to 30-40 years), infecting through sugar Food, into plants, animals, vegetables and finally into humans. Dioxin has two sources: 1- from the Agent Orange war sprayed by the US. 2-from industrial, domestic and medical waste, contains a lot of plastic through incomplete combustion.

According to the late Dr. Ton That Tung, dioxin is a carcinogenic agent and especially liver cancer. Moreover, according to a recent study by the American Academy of Sciences, dioxin is the cause of prostate cancer of US veterans who have been exposed to Agent Orange in Vietnam. In addition, it has been shown to be the cause of a wide range of cancers such as: soft tissue cancer, malignant lymphoma, respiratory cancer (lung, bronchus, trachea, larynx), disease multiple myeloma .

* Carcinogenic heavy metals such as iron, copper, lead, mercury, cadmium, zinc, especially arsenic . from the air, from wastewater entering the water environment, are attracted by plants to accumulate in leafy vegetables and tubers. , fruit, then people, animals eat, over many years of accumulation will cause cancer. We also had the results of research on metal toxins in accumulated wastewater on rice and grain seeds in suburban HCMC. Arsenic is also a very powerful carcinogen, from industrial waste, mineralized, weathered rock mixed into the air and into the water, especially in groundwater.

People use this water, arsenic accumulates and causes cancer. A lot of people in many villages in Bangladesh and India have cancer and die from drinking arsenic water from groundwater in UNICEF drilled wells. We are also studying this topic in the Mekong Delta because this region has the same conditions as Bangladesh and India.

* Toxic formol : A very toxic organic compound with scientific name, formaldehyde is very volatile, easy to dissolve in water and have a special smell, used in the manufacturing industry of dye, glue, plastic, high su, explosive . Formol is easy to combine with protein to form stable, non-rotting, unremitting but difficult to digest substances. Based on these properties formol is widely used in medicine as a disinfectant, preserving items, preserving organs of the human body and keeping corpses from decaying. However, formol is misused to make noodles, noodles, vermicelli, wet cakes. A very dangerous nature of formol is the ability to create deviations and variations in chromosomes, causing human cancer diseases such as nasal sinus cancer, respiratory cancer (nose, throat, lung), gastrointestinal cancer.

* Borax poison: Korean name has a scientific name: sodium bicarbonate, colorless, soluble in water, antiseptic and very toxic. Welding has the ability to make chewy, crunchy food so it is better to use it to increase the deliciousness of food. When borax is introduced into the body, about 20% accumulates permanently and damages liver cells, testicular atrophy and cancer-causing agents.

* Toxic causes of cancer from tobacco : Toxic smoke is not only for smokers but also more harmful to it, which pollutes the environment, causing inhalers, especially children. The composition of cigarette smoke is very complicated, with more than 4,000 compounds, of which 200 are harmful to health, and even more dangerous is the number of carcinogens for humans to 40. It is the cause of many cancers such as esophageal cancer, laryngeal cancer, oral cancer, nasal cancer, kidney and bladder cancer, pancreatic cancer, genital cancer, cancer. anal and colorectal letters .

* Polycyclic aromatic hydrocarbon (PAH) and benzo (a) pyrene (BaP) : These are toxic carcinogens generated from exhaust gases of engines and industrial incinerators using coal, wood, gasoline . When inhaled, these PAH and BaP reactions combined with DNA cause mutations that increase the risk of lung cancer, abdominal cancer and laryngeal cancer.

* Ethylene and ethylene oxide : These are gases formed during combustion of the engine. From the atmosphere, these substances enter the body, disturbing the structure of macromolecules of proteins and DNA, thereby creating a basic carcinogen.

Prof. Dr. LE HUY BA (Institute of Science and Technology & Environmental Management, HCM City Industrial University)