Serious Health Risks Associated With Grilling – Part II: Polycyclic Aromatic Hydrocarbons

Suggested Article Citation: Garko, M. G. (2014, July). Serious health risks associated with grilling – Part II: Polycyclic aromatic hydrocarbons. Health and Wellness Monthly. Retrieved (insert month, day, year), from www.letstalknutrition.com.

Serious Health Risks Associated With Grilling – Part II: Polycyclic Aromatic Hydrocarbons

 

Michael Garko, Ph.D.

Syndicated Host & Producer – Let’s Talk Nutrition

Introduction

Some of the best moments of summer can be with family and friends at a holiday barbeque enjoying each other’s company and all of the enticing aromatic smells wafting off the grill. As wonderful as such occasions can be, there is, unbeknown to many, a serious health threat lurking in the food-scented, barbeque smoke permeating the air. How could it be that barbeque generated smoke be harmful to a person’s health?

That is exactly the question this July, 2014, issue of Health and Wellness Monthly will address. This is the second article in a series on the health-threatening risks associated with grilling, one of America’s most favorite methods of cooking. Specific attention will be given to polycyclic aromatic hydrocarbons (PAHs), what they are, their sources, how, other than grilling, people can become exposed to them, their health effects, factors affecting the formation of PAHs when grilling and cooking strategies to reduce the formation and health threats of PAHs.

So as not to mislead the reader by the title of the article, PAHs are not toxic chemical compounds exclusive to grilling or barbequing. It is the case that PAHs represent a widespread related collection of naturally- and humanly-created chemicals constituted of various structures and levels of toxicity (see Lah, 2011).

 

What Are PAHs?

PAHs are ubiquitous and dangerous environmental organic pollutants created by the incomplete combustion or burning of carbon-based organic substances derived from natural and human sources such as tobacco, coal, oil, gas, wood and garbage, among other substances (see Agency for Toxic Substances and Disease Registry, 1995). Typically, PAHs do not occur as single compounds but as complex mixtures when found in combustion end-products such as soot and smoke.

In terms of the incomplete combustion of PAHs, the lower the temperature of the fire when carbon-based organic substances are burned and the less oxygen is available, the more incomplete the burning and production of dangerous PAHs (German Federal Environmental Agency, 2012). When there is complete combustion of organic matter, carbon atoms tend not to break apart and bond with oxygen atoms, producing harmless carbon dioxide (CO2), something we exhale when we breathe (see Brown et al., n.d.; German Federal Environmental Agency, 2012).

 

What Are the Sources of PAHs

PAHs, as chemically-dangerous and environmentally-ubiquitous carbon-based organic compounds, are the result of naturally- and humanly-related sources.

 

Natural Sources

PAHs enter into the environment via naturally occurring phenomena such as forest and grass fires, volcanic eruptions, oil seeps and degradation of organic material involving some saprophytic fungi and bacteria and chlorophyllous plants, resulting in PAHs being formed in sediments and fossil fuels (Agency for Toxic Substances and Disease Registry, 1995; German Federal Environmental Agency, 2012; Lah, 2011; Nagpal, 1993; U.S. Geological Survey, 2014).

 

Human Sources

Human sources are the major contributors of PAHs contaminating the environment and people. PAHs derived from human sources and related to industrial activities include the burning of fossil fuels, iron smelting, petroleum refining, production of coke, carbon black, coal tar and asphalt, thermal power generation, waste incineration, tar paper production, wood preservation using creosote, and electric power generation, among other industrial-related sources (Agency for Toxic Substances and Disease Registry, 1995; German Federal Environmental Agency, 2012; Nagpal, 1993; U.S. Geological Survey, 2014).

Other human-related sources activities implicated with putting humans in contact with PAHs include toys and children products, tobacco smoke, vehicle exhaust, leaking motor oil, tire particles, crumbling asphalt, parking lot and driveway sealants, consumer and food (i.e. contaminated crops and manufactured/processed foods containing PAHs), indoor fireplaces, grilling/barbequing, among other human-related sources (Agency for Toxic Substances and Disease Registry, 1995; Danish Ministry of the Environment, 2012; German Federal Environmental Agency, 2012; Van Metre, 2006;).

 

What is the Reach and Nature of Polycyclic Aromatic Hydrocarbons?

The reach of PAHs derived from natural and human sources is far and wide. PAHs are found across the planet polluting the air, water, soil and contaminating a variety of consumer goods and products, including food (i.e., food crops and manufactured foods) (Agency for Toxic Substances and Disease Registry, 1995; Blumer & Youngblood, 1975; German Federal Environmental Agency, 2012; U.S. Geological Survey, 2014).

 

Characteristics of PAHs

Given their complex chemical structure, PAHs tend not to break down so readily (taking weeks to months) and, thus, are persistent and pervasive toxins in the environment, posing a real health threat to humans, other life forms (i.e., plants and animals) and the planet (see Agency for Toxic Substances and Disease Registry, 1995; Perrin, 2012).

In addition to being toxic, globally pervasive and breaking down slowly, PAHs tend to evaporate rather quickly into the atmosphere when exposed to heat, evaporate from surface soils and waters, travel long distances in the air, attach or stick tightly to soil, dust, soot, smoke and sediment particles, resist dissolving easily in water and resist combustion or otherwise not burn easily. These different properties of PAHs come into play as they make their way into the air, water and soil of the environment and existence and health of people, other animals and plants. One feature of PAHs that illustrates this point is that “[t]he PAH content of plants and animals living on the land or in water can be many times higher than the content of PAHs in soil or water” (Agency for Toxic Substances and Disease Registry, 1995, p.2).

 

 

PAHs in the Atmosphere

PAHs find their way into the environment largely as emissions released into the atmosphere from natural and human sources such as volcanic eruptions, forest and grass fires, waste incineration, residential wood burning, vehicle exhaust and industrial and refining processes, among other routes. PAHs can evaporate into the air from contaminated soil and surface waters. Once in the atmosphere, PAHs exhibit an ability to travel fairly long distances before finding their way back to the earth’s surface by way of rainfall and particulate settling. PAHs settle to the ground from the atmosphere and get deposited on soil, bodies of water such as lakes and streams and vegetation (Agency for Toxic Substances and Disease Registry, 1995).

 

PAHs in the Water

PAHs do not dissolve readily in water. They are often discovered in air pollution as particulate matter and tend to adhere to surfaces, thereby, attaching easily to sediment particles and resulting in high sediment concentrations in rivers, lakes and streams. Their ability to stick to solid particles and settle to the bottom of rivers and lakes is one of the primary characteristics of PAHs (see Perrin, 2012; Agency for Toxic Substances and Disease Registry, 1995). Soil erosion is another way PAHs can be deposited in lakes, rivers and streams. PAHs can also enter into surface water by way of toxic discharges from industrial facilities and waste water treatment plants. (Agency for Toxic Substances and Disease Registry, 1995; Nagpal, 1993).

 

PAHs in the Soil

PAHs can be released into the soil by way of hazardous industrial waste sites of one type or another. They tend to stick tightly to soil particles and are known to stay close to the surface of the ground. The PAHs contained in soils also have the ability to contaminate underground water and any crops growing in soil contaminated with PAHs (Agency for Toxic Substances and Disease Registry, 1995; Brown et al. n.d.; Blumer & Youngblood, 1975).

 

PAHs in Consumer Goods and Products

Commercially, PAHs are found in the manufacture of medicines, tobacco products (e.g., smokeless tobacco), smoked food products (e.g., liquid smoke food flavorings, smoked cheeses, turkey, pork, chicken, beef, mussels and fish), dyes, protective coats, coatings and adhesives, lubricating materials, products made of rubber or plastics (e.g., tool handles, clogs, beach sandals, toys and childcare products, sports equipment, bicycle handlebars, watch straps, etc.), tattoo inks, electronic products, photographic products, pesticides, asphalt for road construction, tires, sealcoat for pavements and driveways, tar for roofing, wood preservatives and coal briquettes, among various other commercial products (see German Federal Environmental Agency, 2012;Nagpal,1993; Van Metre et al., 2006).

To Be Continued

 

References

 

Agency for Toxic Substances and Disease Registry (ATSDR) (1995). Toxicological profile for polycyclic aromatic hydrocarbons (PAHs). Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. Retrieved May 15, 2014, from http://www.atsdr.cdc.gov/ToxProfiles/tp69-c1-b.pdf.

Blumer, M. & Youngblood, W.W. (1975, April). Polycyclic aromatic hydrocarbons in soils and recent sediments: Science, 188 (4183), 53-55. Retrieved May 15, 2014.

Danish Ministry of the Environment (2012). PAHs in toys and childcare products: Survey of chemical substances in consumer productsNo. 1142011. Retrieved May 15, 2014 from http://www2.mst.dk/udgiv/publications/2012/01/978-87-92779-49-6.pdf.

German Federal Environmental Agency (2012). Polycyclic aromatic hydrocarbons: Harmful to the environment! toxic! inevitable?“Retrieved May 15, 2014 from http://www.umweltbundesamt.de/sites/default/files/medien/publikation/long/4395.pdf.

Lah, K. (2011). Polycyclic aromatic hydrocarbons (PAHs) – abridged. Retrieved May, 15, 2014 from http://toxipedia.org/display/toxipedia/Polycyclic+Aromatic+Hydrocarbons+%28PAHs%29+-+Abridged.

Nagpal, N. K. (1993, February). Ambient water quality criteria for polycyclic aromatic hydrocarbons (PAHs). Retrieved May 15, 2014, http://www.env.gov.bc.ca/wat/wq/BCguidelines/pahs/index.html#.

National Cancer Institute (2010). Polycyclic Aromatic Hydrocarbons http://www.cancer.gov/cancertopics/understandingcancer/environment/page34. Retrieved May 15, 2014.

Perrin, C. (2012). Polycyclic aromatic hydrocarbons (PAHs) in urban waters. Retrieved May 15, 2014 from http://ag-econ.ncsu.edu/sites/ag-econ.ncsu.edu/files/epa_professional/perrin/PAH%20fact%20sheet_AG-588-25%20V2.pdf .

U.S. Geological Survey (2014). Polycyclic aromatic hydrocarbons (PAHs). Retrieved May 15, 2014 from http://toxics.usgs.gov/definitions/pah.html.

Van Metre, P.C., Mahler, B.J., Scoggins, M., & Hamilton, P.A., (2006). Parking lot sealcoat–A major source of polycyclic aromatic hydrocarbons (PAHs) in urban and suburban environments: U.S. Geological Survey Fact Sheet 2005-3147. Retrieved May 15, 2014 from http://pubs.usgs.gov/fs/2005/3147/.

Suggested Article Citation: Garko, M. G. (2014, July). Serious health risks associated with grilling – Part II: Polycyclic aromatic hydrocarbons. Health and Wellness Monthly. Retrieved (insert month, day, year), from www.letstalknutrition.com.