The Truth About Carbon Dioxide Toxicity

There is plenty of scientific literature about toxicity levels of carbon dioxide (CO2). Despite media alarm we show how scientists have proven CO2 is not only safe, but an important benefit to life.

Do scientists believe CO2 in high concentrations is a danger to life? Well, studies have shown that full-face motorbike helmets retain an astonishing 20,000ppm of carbon dioxide. Bikers working long hours as couriers are the most exposed to this so-called ‘toxic’ gas touted as a ‘pollutant’ by climate alarmists at the comparatively microscopic level of only 400ppm.

So bikers are every day inhaling levels FIFTY TIMES higher than climate ‘experts’ regard as safe. So much for experts!

But what are the known effects of long-term breathing of high levels of CO2?

Very few studies exist related to long-term exposure at lower CO2 levels, elevated above ambient. This is ascribed to logistical reasons as it is difficult to conduct experiments for the duration of a human life-span.

As with other aerobic organisms, CO2 is the waste product of human exhalation. Breathing delivers oxygen to where it is needed in the body and removes carbon dioxide thereby exchanging oxygen and carbon dioxide between the body and the environment.

International Space Station (ISS) crew members have reported symptoms associated with acute CO2 exposure at levels of 5,000 to 6,600 ppm CO2. Commonly reported symptom includes headache, lethargy, mental slowness, emotional irritation, and sleep disruption (Law et al. 2010).

However, when looking to determine impacts on astronauts NASA acknowledges there are no studies into the safe levels for long-term exposure to CO2 (Cronyn et al. 2012). As such, they estimated the maximum allowable CO2 concentration limits, for long term (1,000 day) habitation of submarines and spacecraft, at 5,000 ppm (James and Macatangay 2009).

In the US the safe exposure limits for an 8-hour working day was decided in 1946. This is set at 5,000 ppm (OSHA 2012). This limit is based on observations of fit and healthy submariners (Scott et al, 2009). A value of 40,000 ppm is considered immediately dangerous to life and health given that a 30-minute exposure to 50,000 ppm produces intoxication, and concentrations around 70,000 ppm produce unconsciousness (NIOSH 1996). Additionally, acute toxicity data show the lethal concentration for CO2 is 90,000 ppm (9{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}) for a 5 minute exposure.

For worker safety, the US Occupational Safety and Health Administration sets a permissible exposure limit (PEL) for CO2 of 5,000 parts per million (ppm) (or 0.5 {154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}) over an 8-hour work day (OSHA 2012). They report that exposure to levels of CO2 above this can cause problems with concentration, an increased heart rate, breathing issues, headaches and dizziness.

Examination of the table below reveals the effects of various levels of CO2 on the human body:

Carbon dioxide (CO2) is also a feedback mechanism in helping to regulate the rate of breathing (Patton and Thibodeau 2009) since the blood level of CO2 acts directly on the respiratory centres in the brain stimulating the nerves that activate the respiratory muscles. High levels of carbon dioxide correspond with high levels of acid (low pH) in the blood and signal the need for more exchange with oxygen.

Inhaling high levels of CO2 results in high concentrations in the blood (hypercapnia) associated with a decrease in blood pH (increased acidity) resulting in a condition known as acidosis.

Body Adaptation to Long-term Exposure

With long-term, continuous exposure to high levels of CO2 human organs adapt and regulate for increased CO2 and acidity in the blood. To compensate the body employs pH buffering systems in the blood, along with increased breathing to flush out CO2 in the bloodstream; more activity in the kidneys to restore pH balance, plus widening of the blood vessels (Burton 1978; Eckenhoff and Longnecker 1995). Cerebral blood flow (CBF) increases to effectively wash out CO2 from brain tissue and helps regulate central pH (Ainslie and Duffin, 2009). Sliwka et al. (1998) found that cerebral blood flow is increased in the presence of 7,000 ppm (0.7{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}) CO2 by as much as 35{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}.

Depletion of Oxygen is the Real Danger

Studies indicate that it is less about CO2 but more about the levels of available oxygen (O2) which determine the seriousness of health impacts.

“What may be unclear in some cases is whether the sub-acute (sub-toxic) effects at modestly-elevated levels of CO2 in air stem from more from exposure to higher levels of carbon dioxide or whether they are due to reduced levels of oxygen. In an enclosed space such as a tight home or an enclosed basement or work space, increasing the level of CO2 is likely to simultaneously reduce the proportion of Oxygen (O2) in that same breathing air.

Some experts opine that complaints that seem to be associated with high CO2 problem in many if not most circumstances are likely to be actually due to the corresponding reduction in available oxygen in air rather than high toxicity levels of CO2 in the air.”

See: https://inspectapedia.com/hazmat/Carbon_Dioxide_Hazards.php

CO2 is carbon dioxide, and O2 is oxygen. Both are gases at temperatures that normally occur on the Earth’s surface. Oxygen equates to 21 percent of the air you breathe; carbon dioxide is a very tiny 0.04 percent.

For example, if all the parts of the air you breathe = $100, then oxygen accounts for $21 and carbon dioxide accounts for only about 4 pennies (4 cents).

FACT: 100 liters of air contains:

  • 20.9 liters of oxygen (20.9{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117})
  • 0.04 liters of CO2 (0.04{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117})

It is becoming more widely known that photosynthesis in green plants turns water and CO2 into more biomass and O2. Horticulturalists and farmers know CO2 is not a pollutant nor is it ‘toxic’ per se because it is plant food. Atmospheric CO2 is currently 410ppm. If CO2 were reduced to 100 ppm life on earth would die. CO2 at 1,400 ppm or higher is the level at which life on our planet historically thrived.

The gas throughput is often simply put as CO2->green plant->O2. But this is an oversimplification. Plants don’t convert CO2 to O2. They convert CO2 and H2O into O2 and sugar.

Below is a video demonstrating how CO2 operates as an essential plant food:

As an illustration, a healthy 32-foot tall ash tree produces about 260 pounds of oxygen annually. A typical person consumes 386 pounds of oxygen per year. Therefore, two medium-sized, healthy ash trees can meet the oxygen requirement of one person for one year.

CO2 Health Impacts in Confined Indoor Spaces

A considerable amount of recent literature worldwide has documented CO2 impacts in classrooms from kindergartens to universities (Bako-Biro et al 2011; Widory and Javoy 2003; Kukadia et al. 2005; Dijken et al. 5 2005; Branco et al. 2015; Heudorf et al. 2009; Santamouris et al. 2008; Ferreira and Cardoso 2014; Gaihre et al. 2014; Jurado, et al. 2014; Lee and Chang 2000; Muscatiello et al 2015; Carreiro-Martins et al. 2014).

Most agree levels of CO2 in 20-50{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} of classrooms commonly exceed 1,000 ppm and are often as high as 6,000 ppm for extended periods. Recorded impacts on health are of a minor nature but include sneezing, rales, wheezing, rhinitis, and asthma (Carreiro-Martins et al. 2014; Ferreira and Cardoso 2014).

Other symptoms; i.e. cough, headache, and irritation of mucous membranes, were also identified (Ferreira and Cardoso 2014). Lack of concentration was associated with CO2 levels above 1,000 ppm. Gaihre et al. (2014) show some neuro-physiologic symptoms (i.e., headache, fatigue, difficulty concentrating) at CO2 levels greater than 1,000 ppm (Muscatiello et al. 2015).

In workplaces such as offices, high CO2 level impacts show a range of mild health effects similar to classrooms, depending on the number or density of workers and the types of ventilation systems (Lu et al. 2015; Tsai et al. 2012, Seppanen et al. 1999). Such studies make a link between CO2 levels in offices and Sick Building Syndrome (SBS) with workers complaining of headaches, dizziness, fatigue, respiratory tract symptoms, eye symptoms, nasal and mucous membrane symptoms (Seppanen et al. 1999; Lu et al. 2015; Tsai et al. 2012; Vehviläinen et al. 2016). Seppanen et al. (1999).

However, such studies did not account for other airborne contaminants as the cause (Zhang et al. 2016).

With vehicle travel higher levels of CO2 are noted particularly where there are multiple passengers for relatively long journey times. CO2 levels may reach 5,000 ppm after less than an hour of driving with two people in a car with only internal air (Gładyszewska-Fiedoruk 2011).

Measurements show five people in a car with recirculated air levels of CO2 can exceed 10,000 ppm (1{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}) after only 28 minutes, a level known to result in respiratory acidosis (Constantin et al. 2016).

Crowded buses consistently reach average CO2 concentrations of > 2,500 ppm (Chiu et al 2015).

Airliners can contain levels of around 2000 ppm for the duration of the flight (Gładyszewska-Fiedoruk 2012). Measurements on an Italian submarine showed a steady increase to 5000 ppm CO2 after 2 hours of being submerged (Ferrari et al. 2005).

Extremely high CO2 concentrations (10,000-20,000 ppm) are commonly found inside motorcycle helmets in both stationary and moving situations (Bruhwiler et al. 2005).

Studies affirm low levels on oxygen (O2) alongside high levels of carbon dioxide (CO2) is the real threat to life:

“Acute high-level CO2 exposure in the presence of low-level O2 can produce significant persistent adverse health effects including headaches, attacks of vertigo, poor memory and ability to concentrate, difficulty sleeping, tinnitus, double vision, photophobia, loss of eye movement, visual field defects, enlargement of blind spots, deficient dark adaptation, and personality changes.

Prolonged low-level CO2 exposure (<3{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}) in the presence of normal O2 can produce relatively benign short-term effects in healthy, young adults. One effect, alterations in bone metabolism and related blood calcium concentrations, however, may have potentially longer-lasting adverse effects in both healthy and sensitive populations. The bone and calcium alterations in animals have been associated with renal calcification at CO2 concentrations ranging from 0.3 to 15{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117}.” [1]

Remember, CO2 is actually made of TWO molecules of oxygen for ONE single molecule of carbon!

https://www.netl.doe.gov/publications/proceedings/04/carbon-seq/169.pdf

Common Definitions:

“Carbon Dioxide (CO2) – A colourless, odourless gas produced by burning carbon and organic compounds and by respiration, and absorbed by plants in photosynthesis.” – Compact Oxford English Dictionary

“Carbon Dioxide (CO2) – A heavy colorless odorless atmospheric gas. Source: respiration, combustion. Use: during photosynthesis, in refrigeration, carbonated drinks, fire extinguishers.” – Encarta Dictionary

“Carbon Dioxide (CO2) – A heavy colorless gas that does not support combustion, dissolves in water to form carbonic acid, is formed especially in animal respiration and in the decay or combustion of animal and vegetable matter, is absorbed from the air by plants in photosynthesis, and is used in the carbonation of beverages.” – Merriam-Webster Dictionary

“Carbon Dioxide (CO2) – A colorless, odorless, incombustible gas, CO2, formed during respiration, combustion, and organic decomposition and used in food refrigeration, carbonated beverages, inert atmospheres, fire extinguishers, and aerosols.” – The American Heritage Dictionary

“Carbon Dioxide (CO2) – A colorless, odorless, incombustible gas that is produced naturally in breathing, combustion, and decomposition, and commercially for use in dry ice, fire extinguishers, and carbonated beverages.” – Wordsmyth Dictionary

Basic Facts of Carbon Dioxide:

  • Carbon Dioxide (CO2) is a natural part of Earth’s Atmosphere (NASA)
  • Carbon Dioxide (CO2) levels in the atmosphere are only at 0.04{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} (400ppm) (Source)
  • Carbon Dioxide (CO2) is not toxic until 5{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} (50,000ppm) concentration (Source)
  • Any detrimental effects of Carbon Dioxide (CO2) including chronic exposure to 3{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} (30,000ppm) are reversible (Source)
  • OSHA, NIOSH, and ACGIH occupational exposure standards are 0.5{154653b9ea5f83bbbf00f55de12e21cba2da5b4b158a426ee0e27ae0c1b44117} (5,000 ppm) Carbon Dioxide (CO2) (Source)
  • Submarine Crews live and work in a Carbon Dioxide (CO2) rich environment of 3,500 to 4,100 ppm on average (Source)

[1] HUMAN HEALTH RISK ASSESSMENT OF CO2: SURVIVORS OF ACUTE HIGH-LEVEL EXPOSURE AND POPULATIONS SENSITIVE TO PROLONGED LOW-LEVEL EXPOSURE Susan A. Rice, Ph.D., D.A.B.T. Susan A. Rice and Associates, Inc., Grass Valley, CA, USA


John O’Sullivan is CEO of Principia Scientific International CIC, a registered UK non-profit that relies solely on public contributions. Please donate today.

 

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    Robert Beatty

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    CO2 is also a heavy gas which allows it to reach high concentrations at low levels. As a miner, we were trained to beware of going into poorly ventilated tunnels where CO2 might collect. It is worth noting that a large store of very soluble CO2 exists in the oceans as the bicarbonate ion. The relative concentrations of CO2 in sea water are given as aqueous (1%), bicarbonate ion (93%) and carbonate ion (6%). This ion is only stable at temperatures below 50oC. The highest sea surface temperature recorded was 35.6oC in the Persian Gulf. However, large meteor impacts with the ocean can cause sea temperatures to raise above the disassociation temperature, resulting in large release of CO2 into the atmosphere. If the meteor is large enough, the release of CO2 can reach suffocating levels on earth. Oceans can legitimately be considered as brisant explosives awaiting a suitable detonion. More details available at http://bosmin.com/SeaChange.pdf

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