scholarly journals Inappropriate Use of Risk Assessment in Addressing Health Hazards Posed by Civil Aircraft Cabin Air

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Howard C V
Keyword(s):  
Risk Assessment ◽  
Airline Industry ◽  
Scientific Literature ◽  
Inhalation Exposure ◽  
Complex Mixture ◽  
Subsequent Development ◽  
Engine Oil ◽  
High Dose ◽  
Military Aircraft ◽  
Specific Chemical

Over decades, the airline industry has published considerable documentation on the potential for inhalation exposure to organophosphates and other toxins sourced to engine oil fumes supplied by “bleed air” systems, which are used on most commercial and military aircraft. Case studies on the subsequent development of neurological and other symptoms reported by crewmembers have also been widely documented. However, airline industry reviews tend to define toxicity of engine oil fumes according to a single toxicological endpoint - Organo Phosphate Induced Delayed Neuropathy (OPIDN) – which is acknowledged to be the result of a very high dose of exposure to a specific chemical, Tri-Ortho Cresyl Phosphate (TOCP). Industry reviews typically argue that the low levels of TOCP in aviation engine oils justifies the safety of continuing to use unfiltered engine bleed air to ventilate civil and military aircraft cabins. In fact, this approach ignores the routine presence and toxicity of a complex mixture of OPs in oil fumes supplied by engine bleed air systems and ignores the type of neurological symptoms that crews report (i.e., not OPIDN). The industry approach also ignores the scientific literature on repeated low-dose exposure to OPs over extended periods (particularly relevant for airline crewmembers) and the variable susceptibility of individuals to toxicological damage. This paper reviews the above-mentioned studies and presents the scientific literature that should be considered to make a realistic risk assessment of the hazards of aircraft engine bleed air.

scholarly journals Inappropriate Use of Risk Assessment in Addressing Health Hazards Posed by Civil Aircraft Cabin Air

2020 ◽  
Vol 4 (5) ◽  
Author(s):  
Howard CV
Keyword(s):  
Risk Assessment ◽  
Airline Industry ◽  
Scientific Literature ◽  
Complex Mixture ◽  
Aircraft Engine ◽  
High Dose ◽  
Aircraft Cabins ◽  
Inappropriate Use ◽  
Civil Aircraft ◽  
Toxicological Risk Assessment

Toxicological reviews of data on Aerotoxic Syndrome that have been widely referenced by the airline industry tend to use a toxicological endpoint, Organo-Phosphate Induced Neuropathy (OPIDN), that is acknowledged to be the result of a very high dose of organophosphate exposure. Additionally, the reviews tend to only address one chemical, Tri-Ortho Cresyl Phosphate (TOCP), ignoring the presence of other toxic compounds in a complex mixture. In using this to justify the safety of the continued use of unfiltered engine bleed air to ventilate civil aircraft cabins, this represents a misuse of toxicological risk assessment. The approach totally ignores the scientific literature on repeated low-dose exposure to OPs over extended periods, the constant presence of a complex mixture of OPs in engine bleed air and their overall toxicity and the variable susceptibility of individuals to toxicological damage. This paper lists the above-mentioned studies and reviews a sub-set. We present the scientific literature that should be considered to make a realistic risk assessment of the hazards of aircraft engine bleed air.

scholarly journals A Novel Methodology for Health Hazard and Risk Assessment of Dermal and Inhalation Exposure

2021 ◽  
Vol 333 ◽  
pp. 10002
Author(s):  
Rafeqah Raslan ◽  
Mimi H. Hassim ◽  
Nishanth G. Chemmangattuvalappil ◽  
Denny K. S. Ng
Keyword(s):  
Risk Assessment ◽  
Early Stage ◽  
Health Hazard ◽  
Inhalation Exposure ◽  
Liquid Detergent ◽  
Specific Chemical ◽  
Household Products ◽  
Systematic Methodology ◽  
Hazard And Risk ◽  
Hazard And Risk Assessment

Household products such as dishwasher products and multipurpose cleaners may contain specific chemical ingredients to meet the consumer needs. However, some of the ingredients may result in skin and respiratory irritation. Thus, a systematic methodology to estimate the extent of hazard and risk for consumers’ exposure to the products is needed. In this work, an index-based methodology is presented to estimate the severity of the hazards and risks of the ingredients at during the early stage of product design. Higher score was assigned to the higher potential of hazard and risk, and vice versa. The hazard potential was determined based on hazard classification by the Global Harmonised System (GHS). Risk assessment was performed by considering the Margin of Exposure (MOE) and Risk Characterization Ratio (RCR). To demonstrate the proposed methodology, the dermal and inhalation hazards as well as risks from ingredients used in formulation of liquid detergent were evaluated.

Modification of endocrine active potential by mixtures

2003 ◽  
Vol 75 (11-12) ◽  
pp. 2069-2079
Author(s):  
Kevin Gaido ◽  
Li You ◽  
S. Safe
Keyword(s):  
Risk Assessment ◽  
Complex Mixture ◽  
Antagonist Activity ◽  
Specific Chemical ◽  
Receptor Modulator ◽  
Synthetic Receptor ◽  
Active Chemical ◽  
Multiple Variables ◽  
Halogenated Aromatics ◽  
Hazard Risk Assessment

Wildlife and humans are exposed to a complex mixture of endocrine active chemicals. The activity of a specific chemical in any mixture can be modified through interactions with other components of the mixture. The toxic equivalency factor (TEF) approach for risk assessment was developed for chemicals such as halogenated aromatics that induce their effects through ligand-activated receptors. For persistent halogenated aromatic AhR agonists, this approach has some utility. However, the use of the TEF approach for endocrine active compounds is confounded by the unique tissue- and response-specific activities of these structurally diverse compounds. The term selective receptor modulator describes the ability of a natural or synthetic receptor ligand to manifest agonist activity in one tissue or for one response and antagonist activity in other tissues or for another response in the same tissue. Thus, it is possible for chemicals in a mixture to behave in an additive manner for one response and an antagonist manner for another response. A mechanisms-based hazard risk assessment of endocrine active chemical mixtures must account for these multiple variables.

scholarly journals Ultrafine particle levels measured on board short-haul commercial passenger jet aircraft

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Susan Michaelis ◽  
Tristan Loraine ◽  
C. V. Howard
Keyword(s):  
Health Effects ◽  
Ultrafine Particle ◽  
Inhalation Exposure ◽  
Engine Oil ◽  
Engine Operation ◽  
Specific Chemical ◽  
Aircraft Cabins ◽  
Adverse Health Effects ◽  
Adverse Health ◽  
Air Supply

Abstract Background Airline crew members report adverse health effects during and after inhalation exposure to engine oil fumes sourced to the air supply system onboard commercial and military aircraft. Most investigations into the causal factors of their reported symptoms focus on specific chemical contaminants in the fumes. The adverse health effects reported in aircrew exposed to the aircraft air supply, bled unfiltered off the engine or Auxiliary Power Unit (APU) may be related to particulate exposures, which are widely known to effect health. While oil contaminates the aircraft air supply, some suggest that this will only occur when there is a bearing seal failure, others document that there is low level oil contamination of the air supply during normal engine operation. This brief pilot study explores whether particulate exposure may be associated with the normal engine/APU and air supply operation and to therefore increase the understanding that UFP exposures may have on crew and passengers. Methods An ultrafine particle counter was utilised by an experienced airline captain in the passenger cabin of four short-haul commercial passenger aircraft. All flights were under 90 min on aircraft from two different carriers ranging from 7 months to 14 years old. Results UFP concentrations showed maximum concentrations ranging from 31,300 to 97,800 particles/cm3 when APU was selected on as a source of air on the ground and with engine bleed air and the air conditioning packs selected on during the climb. In 2 of the 4 flights the peaks were associated with an engine oil smell. Increases in UFP particle concentrations occurred with changes in engine/APU power and air supply configuration changes. Conclusions This study identified increases in UFP concentrations associated with engine and APU power changes and changes in air supply configuration. These results correlated with times when engine and APU oil seals are known to be less effective, enabling oil leakage to occur. The concentrations reached in the passenger cabins exceeded those taken in other ground-based environments. UFP exposures in aircraft cabins during normal flight indicates there will be health consequences for long serving aircrew and some passengers.

Evaluation of hippocampus in rhesus monkeys after chronic (1-year) inhalation exposure to marijuana: I. Electron microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 398-399
Author(s):  
A.M. Andrews ◽  
S.W. Wilson ◽  
A.C. Scallet ◽  
S.F. Ali ◽  
J. Bailey ◽  
...  
Keyword(s):  
Synaptic Vesicles ◽  
Rhesus Monkeys ◽  
Low Dose ◽  
Inhalation Exposure ◽  
Synaptic Cleft ◽  
High Dose ◽  
Withdrawal Time ◽  
Treatment Groups ◽  
Ultrastructural Evidence ◽  
Male Rhesus

Exposure of rhesus monkeys (Macaca mulatta) to marijuana via inhalation or to intravenous delta-9-tetrahydrocannabinol (THC), reportedly caused ultrastructural evidence of increased synaptic width. Chronic marijuana smoke in a single rhesus monkey examined after a six month withdrawal time caused ultrastructure changes in the septal, hippocampal and amygdala regions; the synaptic cleft was widened, electron opaque material was found in the cleft and in the pre- and postsynaptic regions, with some clumping of the synaptic vesicles. The objective of our study was to assess neuropathological alterations produced by chronic inhalation of marijuana smoke.Nineteen male rhesus monkeys, 3-5 years of age and weighing 3-8 kg, were divided into four treatment groups: a) sham control, b) placebo smoke (7 days/ week) c) low dose marijuana (2 times/week with 5 days/week sham) and d) high dose marijuana (7 times/week). A smoke exposure consisted of smoke from one cigarette (2.6% THC) burned down to 10 mm butt length. Smoke was administered via smoke generator (ADL II, Arthur D. Little, Inc. Cambridge, MA) and nose-mouth only masks (local production) equipped with one-way valves.

Risk assessment and forest pest management

1991 ◽  
Vol 67 (5) ◽  
pp. 486-492
Author(s):  
Frank N. Dost
Keyword(s):  
Risk Assessment ◽  
High Dose ◽  
Forest Pest ◽  
Potential Harm ◽  
Dose Rates ◽  
Human Risk ◽  
Forest Pest Management ◽  
The Subject ◽  
Management Method ◽  
Normal Background

Prediction of potential harm, or risk assessment, is essential to planning for any vegetation management method, but the concepts and process are often not understood. This discussion is a highly simplistic description of the basic elements of toxicology and estimation of risk in excess of the high normal background. All chemical risk is directly related to the dose acquired by the subject or population. In the case of cancer, added human risk that may be associated with very low doses is expressed as a probability that is estimated by extrapolation from observations at high dose rates. Reasons for such an indirect approach and weaknesses of the present process are described.

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