Background on Toxins
In science, a toxin generally refers to a poisonous substance produced in living cells or organisms. Toxins can be categorized as exotoxins (secreted by an organism) or endotoxins (toxins that are part of bacteria). Exposure to a toxin can cause serious harm to a variety of organisms when the toxin is absorbed by the body into the tissues (Science Learning Hub, n.d.). The magnitude or overall effect of exposure to a toxin can vary, ranging from minor insult to more deadly outcomes, so immediately identifying the presenting toxin and managing it are imperative to increase the likelihood of survival.
People can be exposed to toxins during everyday life—whether it is through water, food, air, bacteria, fungi, plants, or their own home or environment (CDC 2017). Given the probability of contact with toxins, it is important for there to be a growing awareness of the most common toxins and how to address outcomes that may arise from intentional or unintentional exposure. Of course, the first-line approach is to always make attempts to avoid exposure, as the risks of exposure appear to largely outweigh the benefits.
It has become commonly known that humans can be exposed to a number of toxins on any given day or during their lifetime, and while some may not cause significant harm, there are those toxins that can cause sickness or even lead to death. These toxins can be identified in almost every facet of life.
Toxins in the Air
Firstly, we begin with the air, which is not always free from contaminants (NH Department of Environmental Services, n.d.). Unfortunately, the air can become filled with a number of natural and man-made substances. Toxic air pollutants can present as vapors or particulate matter, with examples including cadmium, chromium, mercury, or lead compounds. Several states have developed initiatives to reduce emissions of some of these toxic pollutants and ultimately prevent the detrimental effects that long-term exposure can produce (NH Department of Environmental Services, n.d.). The adoption of toxic control measures, more stringent vehicle standards, and cleaner fuels has yielded lower levels of exposure to the toxins in the air in some states (California ARB, n.d.). Toxicologists are instrumental in helping identify the primary toxic substances or chemicals that are of the greatest concern and the levels of exposure; performing risk assessments; and arriving at some reasonable toxicological certainty after performing their assessment (TCAS 2020).
Toxins in Water
Homes with lead pipes, faucets, and fixtures often are the largest source of lead in drinking water, but natural waterways are not immune with the well-known case of Flint, Michigan, illustrating the potential for toxic levels to be consumed by humans. Lead in drinking water can cause cardiovascular issues, decreased kidney function, and reproductive problems, and other notable issues that can occur, especially in children who are exposed, include developmental problems, behavioral issues, or learning disabilities (US EPA 2019). Other chemicals that can be present in drinking water and are regulated by the US EPA due to their potential to cause harm include chlorine, trihalomethanes, and chemicals used in pesticides and fertilizers, such as nitrate and nitrite (US EPA 2020).
Toxins in Food
Some natural toxins are present in food as a result of defense mechanisms of plants or as a result of animals’ ingestion of toxin-producing microorganisms, which have the potential to cause adverse effects on human health (WHO 2018). For example, the toxins that can be formed by algae can lead to diarrhea or paralysis in humans, while the ciguatoxins that can be produced by fish contaminated with dinoflagellates can cause nausea, vomiting, and possible neurological issues (WHO 2018). Exposure to cyanogenic glycosides, which are found in about 2,000 plant species, are present in such foods as bamboo roots and cassava. These can contribute to acute cyanide intoxication (e.g., dizziness, headache, mental confusion, or cyanosis), and unfortunately, death can result from cyanide poisoning when the levels within the human body exceed the amount that the human body is able to remove (WHO 2018).
Conclusion
It is imperative for people as well as those who specialize in the area of toxins or toxic chemicals to perform thorough assessments of their daily environments and recognize the potential contaminants that might exist. It is through increasing awareness and knowledge that the absorption or ingestion of these harmful toxins can be avoided, preventing the subsequent consequences that can arise from them.
References
California ARB (California Air Resources Board). n.d. Reducing Toxic Air Pollutants in California’s Communities. Sacramento. https://ww3.arb.ca.gov/toxics/brochure.pdf.
CDC (Centers for Disease Control and Prevention). 2017. “Toxins: Laboratory Response to Toxins.” National Biomonitoring Program. Accessed April 3, 2020. https://www.cdc.gov/biomonitoring/toxins.html.
Miller, Molly. 2017. “Toxic Exposure: Chemicals Are in Our Water, Food, Air, and Furniture: Are the Chemicals We Encounter Every Day Making Us Sick?” University of California San Francisco. Accessed April 3, 2020. https://www.ucsf.edu/news/2017/06/407416/toxic-exposure-chemicals-are-our-water-food-air-and-furniture.
NH Department of Environmental Services (New Hampshire Department of Environmental Services). n.d. “Overview.” Air Toxics Program. Accessed April 3, 2020. https://www.des.nh.gov/organization/divisions/air/pehb/ehs/atp/categories/overview.htm.
Science Learning Hub. n.d. “Poisons and Toxins.” Accessed April 2, 2020. https://www.sciencelearn.org.nz/resources/364-poisons-and-toxins.
TCAS (Toxicological Consultants & Assessment Specialists, LLC). n.d. “Toxic Exposures.” Accessed April 3, 2020. http://experttoxicologist.com/toxicology-toxic-exposures.aspx.
US EPA. 2019. “Basic Information about Lead in Drinking Water.” Ground Water and Drinking Water. Last modified November 18, 2019. https://www.epa.gov/ground-water-and-drinking-water/basic-information-about-lead-drinking-water.
US EPA. 2020. “National Primary Drinking Water Regulations.” Ground Water and Drinking Water. Last modified February 14, 2020. https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations.
WHO (World Health Organization). 2018. “Natural Toxins in Food.” Accessed April 3, 2020. https://www.who.int/news-room/fact-sheets/detail/natural-toxins-in-food.
The SOT Tox Bulletin presents a new opportunity for SOT members to contribute original content to the Communiqué—including science feature articles, commentary and discussion pieces, SOT program impact reports, and more. If you have content to contribute to the Tox Bulletin, please contact SOT Communications Director Michelle Werts.