Impact of Firefighting Aqueous Film-Forming Foams on Human Cell Proliferation and Cellular Mortality

Abstract

Objective

Evaluate the toxic effects of Aqueous Film-Forming Foams used by firefighters for Class B fire suppression in human-derived kidney cells (HEK-293).

Methods

Three widely used AFFFs were collected from fire departments and were added to HEK-293 cells in various concentrations. Seventy-two hours post-treatment, cellular proliferation and toxicity were examined using commercially available kits.

Results

All AFFFs evaluated induced cellular toxicity and significantly decreased cell proliferation, even when cells were treated with concentrations 10-fold lower than the working concentration used for fire suppression.

Conclusion

Despite the reduced usage of PFAS-containing AFFFs in the firefighter work environment, the evaluated AFFFs demonstrated significantly altered cellular proliferation, while also inducing toxicity, indicating the presence of toxic compounds. Both stronger implementation of PFAS-containing AFFFs restrictions and robust evaluation of fluorine-free and next-generation AFFFs are warranted.

In Brief

Firefighters are routinely exposed to per- and polyfluoroalkyl substances (PFAS) through the use of Aqueous Film-Forming Foams (AFFFs) for the suppression of Class B fire, which derive from flammable and combustible liquids, such as gasoline and alcohol. The addition of surfactants and PFAS in the AFFFs allows them to form an aqueous film that can extinguish the fire, while also coating the fuel. As such, AFFFs are often used for fire extinction in airports and military bases.

Exposure to PFAS in the general population may arise from ingestion of contaminated food or water, usage of consumer products containing PFAS, such as non-stick cookware or stain resistant carpets and textiles, and inhalation of PFAS-containing particulate matter. Detection of increased serum PFAS concentrations has been linked to an elevated risk for kidney cancer in humans, and firefighters are known to have increased serum concentrations of certain PFAS after attending training exercises. In the same study it was also observed that the average urinary excretions of 2-butoxyacetic acid (2-BAA) a surfactant often added in AFFFs exceeded the reference limit of the occupationally unexposed population, ranging from 0.5 to 1.4 mmol/mol creatinine.

Furthermore, an increased risk of mortality from kidney cancer has been observed in firefighters compared to the U.S. population. The detrimental health effects of PFAS are exacerbated by their increased half-lives in humans. A recently published study examined the half-lives of short- and long- chained PFAS in the serum of 26 airport employees and observed a wide range of half-lives which was dependent on the length and chemical structure of each substance that was examined. Indicatively, the shortest half-life was described for perfluorobutanesulfonic acid (PFBS), while the linear isomer of perfluorooctanesulfonic acid (PFOS) had the longest half-life (average of 44 days and 2.93 years, respectively), findings which are in agreement with other sources in the literature.

One aspect of this phenomenon could be attributed to renal reabsorption, as humans actively transport PFAS in the proximal tubules. A recently published scoping review of 74 epidemiologic, pharmacokinetic, and toxicological studies examined the relationship between PFAS exposure and kidney-related health outcomes. It was observed that exposure to PFAS was associated with lower kidney function, including chronic kidney disease (CKD), and histological abnormalities in the kidneys, as well as alterations in key mechanistic pathways, that can induce oxidative stress, and metabolic changes leading to kidney disease.

The alarming number of studies showcasing the harmful health effects pertaining to PFAS exposure has led to the banning of the production of AFFFs containing highly toxic, long chain PFAS, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) since 2015. However, this regulation is gradually being implemented across states and little is known about the toxicity of the next generation AFFFs. Based on the above, in the present study we evaluate cellular proliferation and toxicity in kidney-derived cells (HEK-293) that were exposed to three widely used AFFFs.

Read full study below

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Organic solvents and Multiple Sclerosis susceptibility

Abstract

Photo of dichloromethane (DCM) as stored by Irish Air Corps in 2015. DCM was banned in the EU in 2012.
Objective

We hypothesize that different sources of lung irritation may contribute to elicit an immune reaction in the lungs and subsequently lead to multiple sclerosis (MS) in people with a genetic susceptibility to the disease. We aimed to investigate the influence of exposure to organic solvents on MS risk, and a potential interaction between organic solvents and MS risk human leukocyte antigen (HLA) genes.

Methods

Using a Swedish population-based case-control study (2,042 incident cases of MS and 2,947 controls), participants with different genotypes, smoking habits, and exposures to organic solvents were compared regarding occurrence of MS, by calculating odds ratios with 95% confidence intervals using logistic regression. A potential interaction between exposure to organic solvents and MS risk HLA genes was evaluated by calculating the attributable proportion due to interaction.

Results

Overall, exposure to organic solvents increased the risk of MS (odds ratio 1.5, 95% confidence interval 1.2–1.8, p = 0.0004). Among both ever and never smokers, an interaction between organic solvents, carriage of HLA-DRB1*15, and absence of HLA-A*02 was observed with regard to MS risk, similar to the previously reported gene-environment interaction involving the same MS risk HLA genes and smoke exposure.

Conclusion

The mechanism linking both smoking and exposure to organic solvents to MS risk may involve lung inflammation with a proinflammatory profile. Their interaction with MS risk HLA genes argues for an action of these environmental factors on adaptive immunity, perhaps through activation of autoaggressive cells resident in the lungs subsequently attacking the CNS.

Read full study below

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Anecdotal evidence has been emerging for some time of potential illness clusters at Casement Aerodrome to which Multiple Sclerosis has now been added. We are calling for these potential clusters to be investigated by competent authorities.

Suspected illness clusters currently include.

90 Untimely deaths recorded in Irish Air Corps toxic chemical exposure tragedy

Untimely* deaths of serving & former Irish Air Corps personnel

  • 90 verified deaths have occurred in total since 1980 
  • 77 of these deaths have occurred since 2000
  • 53 of these deaths have occurred since 2010
Either the rate of death is accelerating or we are missing many deaths from previous decades or possibly both.
 

3 most significant causes of death

  • 39% of deaths are from cancer
  • 29% deaths are from cardiac
  • At least 15 deaths are from suicide
*We record untimely as dying at or before age 66 (civilian pension age), average age of death is 52 years. We are counting deaths from medical reasons & suicide, we are not counting accidental deaths nor murder.

89 Untimely deaths recorded in Irish Air Corps toxic chemical exposure tragedy

Untimely* deaths of serving & former Irish Air Corps personnel

  • 89 verified deaths have occurred in total since 1980 
  • 76 of these deaths have occurred since 2000
  • 52 of these deaths have occurred since 2010
Either the rate of death is accelerating or we are missing many deaths from previous decades or possibly both.
 

3 most significant causes of death

  • 39% of deaths are from  cancer
  • 29% deaths are from cardiac
  • At least 15 deaths are from suicide
*We record untimely as dying at or before age 66 (civilian pension age), average age of death is 52 years. We are counting deaths from medical reasons & suicide, we are not counting accidental deaths nor murder.

88 Untimely deaths recorded in Irish Air Corps toxic chemical exposure tragedy

Untimely* deaths of serving & former Irish Air Corps personnel

  • 88 verified deaths have occurred in total since 1980 
  • 75 of these deaths have occurred since 2000
  • 51 of these deaths have occurred since 2010
Either the rate of death is accelerating or we are missing many deaths from previous decades or possibly both.
 

3 most significant causes of death

  • 39% of deaths are from  cancer
  • 29% deaths are from cardiac
  • At least 15 deaths are from suicide
*We record untimely as dying at or before age 66 (civilian pension age), average age of death is 52 years. We are counting deaths from medical reasons & suicide, we are not counting accidental deaths nor murder.

A review of health effects associated with exposure to jet engine emissions in and around airports

Background

Airport personnel are at risk of occupational exposure to jet engine emissions, which similarly to diesel exhaust emissions include volatile organic compounds and particulate matter consisting of an inorganic carbon core with associated polycyclic aromatic hydrocarbons, and metals. Diesel exhaust is classified as carcinogenic and the particulate fraction has in itself been linked to several adverse health effects including cancer.

Photo of Alouette III No 196 showing soiling of the tail boom with soot from exhaust gasses.
Method

In this review, we summarize the available scientific literature covering human health effects of exposure to airport emissions, both in occupational settings and for residents living close to airports. We also report the findings from the limited scientific mechanistic studies of jet engine emissions in animal and cell models.

Beechcraft 200 Super King Air No 240 showing soiling of the engine panels with soot from exhaust gasses.
Results

Jet engine emissions contain large amounts of nano-sized particles, which are particularly prone to reach the lower airways upon inhalation. Size of particles and emission levels depend on type of aircraft, engine conditions, and fuel type, as well as on operation modes. Exposure to jet engine emissions is reported to be associated with biomarkers of exposure as well as biomarkers of effect among airport personnel, especially in ground-support functions. Proximity to running jet engines or to the airport as such for residential areas is associated with increased exposure and with increased risk of disease, increased hospital admissions and self-reported lung symptoms.

Conclusion

We conclude that though the literature is scarce and with low consistency in methods and measured biomarkers, there is evidence that jet engine emissions have physicochemical properties similar to diesel exhaust particles, and that exposure to jet engine emissions is associated with similar adverse health effects as exposure to diesel exhaust particles and other traffic emissions.

Read full article journal at BMC

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The layout of the Irish Air Corps base at Casement Aerodrome ensures that aircraft exhaust gasses are blown over populated sections of the airbase when winds are from the south, south east or south west. This includes hangars, offices, workshops and living in accommodation such as the apprentice hostel and married quarters. Calm weather also creates conditions where exhaust gasses linger in higher concentrations.

This results in all Irish Air Corps personnel (commissioned, enlisted, civilian & living-in family) being exposed to emissions from idling aircraft engines, emissions that are known to cause harm.

In the mid 1990s a study of air pollution adjacent to the ramp area at Baldonnel was commissioned. This report relating to this study has gone missing. 

  • Anecdotal evidence suggests increased prevalence of occupational asthma & adult onset asthma amongst serving & former personnel who served in Baldonnel or Gormanston aerodromes. 
  • Older gas turbine engines produce dirtier exhaust gasses.
  • Idling gas turbine engines produce dirtier exhaust gasses.
Below are some of the gas turbine powered Air Corps aircraft that were powered by elderly engine designs.
AircraftRetiredEngine FamilyFirst Run
Alouette III2007Turbomeca Artouste1947
Fouga Magister1999Turbomeca Marboré1951
Gazelle2005Turbomeca Astazou1957
King Air 2002009Pratt & Whitney Canada PT61960
Dauphin II2005Turbomeca Arriel1974

DELAY – DENY – DIE

86 Untimely deaths recorded in Irish Air Corps toxic chemical exposure tragedy

Untimely* deaths of serving & former Irish Air Corps personnel

  • 86 verified deaths have occurred in total since 1980 
  • 73 of these deaths have occurred since 2000
  • 49 of these deaths have occurred since 2010
Either the rate of death is accelerating or we are missing many deaths from previous decades or possibly both.
 

3 most significant causes of death

  • 37% of deaths are from  cancer
  • 29% deaths are from cardiac
  • At least 18% of deaths are from suicide
*We record untimely as dying at or before age 66 (civilian pension age), average age of death is 52 years. We are counting deaths from medical reasons & suicide, we are not counting accidental deaths nor murder.

Ex-Air Corps captain awarded €117,800 over gender discrimination

The Workplace Relations Commission (WRC) has ordered the Minister for Defence to pay €117,814 in compensation to a former female captain in the Air Corps.

WRC adjudication officer, Stephen Bonnlander has made the maximum possible compensation after finding Yvonne O’Rourke was victim to gender discrimination arising from “an unacceptable systematic failure” in the Defence Forces.

After a seven-year battle by Ms O’Rourke, Mr Bonnlander found she was discriminated against on gender grounds in her efforts to secure promotion.

Based at Baldonnell Aerodrome, Ms O’Rourke asserted the Defence Forces discriminated against her on the ground of her gender, in that it treated two maternity leave absences from work as equivalent to the sick absence of a male officer, and consequently gave her a poor performance rating.

The poor rating for 2010 and 2011 impacted on Ms O’Rourke’s ability to go on a mandatory training course which was required to advance to the rank of commander.

Chief Commissioner of the IHREC, Sinead Gibney stated

That Yvonne O’Rourke was treated by the Defence Forces “as if she were a man who had been on long-term sick leave rather than as a pregnant woman”.

By the time Ms O’Rourke was approved by the general officer commanding of the Air Corps to attend the Junior Command and Staff Course (JCSC), her health had deteriorated to the point that she was unable to take up the opportunity and was later retired from the Defence Forces on the grounds of ill health in July 2016.

In a hard-hitting ruling, Mr Bonnlander stated “It beggars belief that women should have been serving in the Irish Defence Forces for decades, without the Forces’ systems and instruction ever having been appropriately updated to ensure they reflect anti-discrimination law as it applies to pregnancy and maternity”.

The hearing at the WRC for Ms O’Rourke’s case against the Minister for Defence spanned six days.

In the long-running action, Ms O’Rourke was represented by the Irish Human Rights and Equality Commission (IHREC), which instructed a senior and junior counsel in the case.

Speaking today, Ms O’Rourke stated:

“I hope that what has been achieved in this outcome and  determination will shine some light on the areas of darkness that needed to be revealed within the Irish Defence Forces. I hope that this small victory will somewhat; smooth the path, pave the way forward, and inspire those left behind, to have their difficulties, hurts, issues and problems of; discrimination, victimisation, bullying, harassment and sexual harassment heard and subsequently addressed in a more expedient fashion than my seven-year struggle.”

Read full report on Irish Times website below

85 Untimely deaths recorded in Irish Air Corps toxic chemical exposure tragedy

Untimely* deaths of serving & former Irish Air Corps personnel

  • 85 verified deaths have occurred in total since 1980 
  • 72 of these deaths have occurred since 2000
  • 48 of these deaths have occurred since 2010
Either the rate of death is accelerating or we are missing many deaths from previous decades or possibly both.
 

3 most significant causes of death

  • 37% of deaths are from  cancer
  • 30% deaths are from cardiac
  • At least 18% of deaths are from suicide
*We record untimely as dying at or before age 66 (civilian pension age), average age of death is 51 years. We are counting deaths from medical reasons & suicide, we are not counting accidental deaths nor murder.

83 Untimely deaths recorded in Irish Air Corps toxic chemical exposure tragedy

Untimely* deaths of serving & former Irish Air Corps personnel

  • 83 verified deaths have occurred in total since 1980 
  • 70 of these deaths have occurred since 2000
  • 46 of these deaths have occurred since 2010
Either the rate of death is accelerating or we are missing many deaths from previous decades or possibly both.
 

3 most significant causes of death

  • 37% of deaths are from  cancer
  • 30% deaths are from cardiac
  • At least 18% of deaths are from suicide
*We record untimely as dying at or before age 66 (civilian pension age), average age of death is 51 years. We are counting deaths from medical reasons & suicide, we are not counting accidental deaths nor murder.