The strands of cloud seen behind aeroplanes are trails of condensed water known as contrails, they are not chemtrails as some believe

Chemtrails contain toxic substances such as barium salts that are 10 thousand times more toxic to your nervous system than lead
Factually inaccurate: The consensus of scientific evidence shows that atmospheric barium levels have not increased due to deliberate programs to deposit barium salts in the atmosphere.
Inadequate support: There is no evidence of a program to deliberately deposit chemicals into the atmosphere via so-called “chemtrails”.
Misleading: Barium salts are not 10,0000 more toxic for the nervous system than lead. Although some barium salts are toxic, their toxicity is comparable to lead.
Aeroplanes sometimes leave a trail of condensed water – a contrail – in their wake depending on factors such as altitude and weather conditions. The water condenses as the hot exhaust from the engine hits air, which is cold at high altitude. Some people have pointed to these as evidence of chemtrails but they are water vapour. There is no evidence of chemicals including barium salts deliberately deposited in the atmosphere to counter climate change or for any other reason.


CLAIM: Chemtrails contain toxic substances such as barium salts that are 10 thousand times more toxic to your nervous system than lead

The claims that aeroplanes are deliberately depositing chemicals in the sky in chemtrails containing barium salts 10,000 times more toxic than lead are taken from a four hour long lecture by self-proclaimed prophet Dr Bill Deagle at the Granada Forum in 2006. The snippet has been posted multiple times on social media including Facebook, where one post received over 37,000 likes and 33,000 shares in March 2023.

Despite the lack of evidence for chemtrails as demonstrated below, the idea retains a small but persistent following. A previous claim by allegedly proving that “Global climate engineering operations are a reality” and “the lingering, spreading jet aircraft trails, so commonly visible in our skies, are not just condensation” has already been reviewed by Climate Feedback.

The consensus of the scientific community has not changed. When asked to comment on the claim in the current video, a spokesperson from the UK Met Office confirmed, “There is no such thing as a ‘chemtrail’, this is a conspiracy theory where people think commercial aircraft are spraying the population with chemicals. The vapor trails left behind aircraft in certain atmospheric conditions are called contrails, as an abbreviation for condensation trails.”

Andreas Schütz, Head of Communication and spokesperson for the German Aerospace Centre responded with a link to the Federal Environment Agency’s own article: “Chemtrails – Dangerous Atmospheric Experiments or Just Fiction?[1] where they clarify the issue (in German).

The contrails sometimes mistaken for chemtrails form naturally as the hot exhaust from the aeroplane engines hit the cold air in the upper atmosphere.

Christiane Voigt, Head of Department for Cloud Physics at the German Aerospace Center Institute of Atmospheric Physics, described the process in more detail: “Contrails are ice crystals, small snow particles and mainly contain water ice. The water condenses from the ambient atmosphere. The ice nucleates [starts to grow] on particle emissions from aircraft engines, mainly soot from the burned hydrocarbon compounds in the kerosene, ice nucleates and is persistent in cold and humid conditions. Contrails only form in 5% of the flights which have this cold and humid conditions mainly related to frontal weather systems”.

Voigt has closely investigated the formation of contrails for her research, which has looked at how different compositions of fuel can affect aircraft induced cloud formation[2,3] from contrails. Although she highlights the potential climate impact of contrails, as she told Science Feedback, “Contrails are not toxic as they mainly constitute water.”

A survey of experts

In 2016 a group of researchers in California led by University of California, Irvine, Earth System Scientist Steven Davis, undertook one of the most comprehensive investigations of chemtrail claims[4]. They were concerned about the absence of scientific studies attempting to engage with claims of chemtrails despite the number of believers in the theory – 2.6% of an international survey of 3105 people at the time of the study. “There have been few attempts to seriously and scientifically evaluate the claims of its proponents”, report the authors of the paper. They hoped that an independent scientific appraisal of the claims would help to disambiguate them.

They sent surveys to hundreds of experts in either atmospheric science and specifically condensation trails, or geochemistry and specifically atmospheric deposition of dust and pollution on the Earth’s surface. They defined experts as researchers who were authors of at least one of the top 100 most cited papers in the field. The surveys included various observations that have been cited as evidence that a program to deposit chemicals in the atmosphere – a secret large scale atmospheric program (SLAP) – is in operation, such as photos of trails left by aeroplanes and analysis of the concentration of elements including barium present in samples of pond sediment, airborne particles and snow. The elemental analyses indicate that the measured element concentrations in the airborne particles are above the maximum contaminant levels, but as one expert pointed out, “The concentrations per unit mass look like average soil or desert dust. The MCL [maximum contaminant levels] values are not relevant, and look to be based on drinking water standards.”

On receipt of 49 responses to the contrail survey and 28 responses to the survey on atmospheric deposition, they found the experts unanimously disagreed with the chemtrail theory as “the most parsimonious [simplest] explanation for the depicted phenomena” in the photos of aeroplane trails. None of the experts noted unusual concentrations of barium.

When asked to reflect on past experience, which includes their past observations of elemental concentrations from samples, 1 expert cited an observation that did not rule out the existence of chemtrails while the remaining 76 of the 77 experts who responded simply stated they “had not encountered evidence that indicates the existence of a secret, large-scale atmospheric spraying program (SLAP)”.

Lead author Davis told Science Feedback that they were not surprised by the scientific consensus in response to the study. ”It takes a lot more effort to explain contrails and soil survey results by a secret large-scale spraying campaign than by natural phenomena.” Despite the strength of the conclusions he said that it was never the goal to settle the debate about chemtrails. “Our paper was intended to provide a scientific counter to conspiracy claims for those in the public who were seeking information on the issue, not to persuade conspiracy theorists who already had strongly held beliefs.”

Barium salts are not 10,000 times more toxic than lead

As for the claim that barium salts are 10,000 times more toxic than lead, this exaggerates the toxicity of barium salts. Some salts such as barium sulphate are insoluble and not readily absorbed. They are used as contrast agents for medical images, for instance to make x-rays of the gastrointestinal tract clearer. Over exposure to barium salts can lead to “vomiting, abdominal cramps, diarrhoea, difficulties in breathing, increased or decreased blood pressure, numbness around the face, and muscle weakness”[5,6] and excessive quantities can be fatal. However the toxicity does not grossly outweigh that of lead[7] as suggested in the video.


Over the course of multiple studies by atmospheric scientists and geochemists for various projects there remains no evidence that chemicals are deliberately dumped in the sky by passing aeroplanes. There is good evidence for the simple explanation that these are ‘condensation of water’ trails. On these points experts in the field agree. In addition, barium salts are not 10000 times more toxic than lead. In summary the highlighted claims in Dr Beagle’s video are false or unsupported.


Published on: 06 Apr 2023 | Editor:

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