What is a contrail made of? Mostly ice, since one of the primary exhaust emissions of a jet aircraft is water vapour, which freezes almost instantly — within about a wingspan behind the aircraft — and forms the visible part of the contrail. If the air is fairly humid, then the contrail can persist for quite a while, and even spread out, turning into a sheet of cloud.
Jet engines also emit the usual things engines emit: carbon dioxide, smoke, and small amounts of unburnt hydrocarbons, oxides of nitrogen and carbon monoxide, plus traces of other compounds. Aircraft emissions are regulated.
Some people think that if a contrail stays in the sky for a long time, this is very unusual, and that it means the government is spraying something in the air, either to change the weather, or to poison people. They call these persistent contrails "chemtrails."
One person who was convinced of this was Clifford Carnicom, who put a report on his website. Below is the kind of lab result such reports are built on — and how to actually read one.
Lab Results
| Substance | Result (mg/L) | MDL | EPA |
|---|---|---|---|
| Aluminum | <0.100 | 0.100 | 0.200 |
| Barium | 0.100 | 0.020 | 2.000 |
| Calcium | <1 | 1 | N/A |
| Magnesium | <1 | 1 | N/A |
| pH (field) | 7.2 | 6.5 to 8.5 | |
| Titanium | <0.050 | 0.050 | N/A |
Understanding the Results
The "Result" column indicates the amount of the substance found in milligrams per liter (mg/L). It's important to use the correct units for analysis. Concentrations may also be expressed as parts per million (ppm), which is equivalent to mg/L, or parts per billion (ppb), where 1 mg/L equals 1 ppm or 1000 ppb. Mixing these units up is the single most common error in "chemtrail lab tests" — in a famous 2007 TV report, a lab result of 68.8 micrograms of barium per litre was announced on air as 6.8 ppm, roughly 100× too high.
The "MDL" (Method Detection Limit) refers to the smallest detectable amount of a substance with 99% confidence that it is not merely instrument noise. If a value is below the MDL, it means the presence of the substance cannot be confirmed—it might be present, but at a concentration too low for the method to distinguish from instrument noise.
The "EPA" column adds perspective by listing the Environmental Protection Agency's allowable limits for drinking water. If no limit is set, the value is marked as "N/A."
Interpreting the Data
Most of the results fall below the MDL, which means the presence of those substances cannot be confirmed. However, some advocates of the "chemtrail" theory claim:
"Tests were ordered for several elements that should NOT be present in normal rain/snow."
Should the results for these elements come back as zero? Here are two critical considerations:
- Even if a substance like aluminum were entirely absent from the samples, the instrument would still report "< MDL" due to noise. A true zero cannot be measured.
- These elements are expected in rainwater. For example, aluminum, the most abundant metal in the Earth's crust (roughly 8% of it), naturally enters rainwater through dust in the air.
Element Analysis
Aluminum: Found naturally in air, soil, and water. According to the CDC's toxicology fact sheet:
- Virtually all food, water, air, and soil contain some aluminum.
- Everyone is exposed to low levels of aluminum daily.
Calcium and Magnesium: Abundant in rocks and airborne dust, with no EPA toxicity limits because they are essentially harmless at these levels.
Barium: Measured at just 5% of the EPA's allowable limit for drinking water. Barium enters the air through activities like mining and burning coal or oil. According to the CDC:
- Barium can be released into air, land, and water during industrial processes.
- Its duration in the environment depends on its specific chemical form.
While barium is present, the levels detected do not pose a significant risk.
pH Analysis
The pH value measures a solution's acidity or alkalinity, where a pH of 7 is neutral. Drinking water typically ranges between 6.5 and 8.5. The recorded pH value of 7.2 in the samples is not unusual for drinking water.
Acid rain is defined as having a pH below 5.0. Rainwater is often slightly acidic (around pH 5.6) due to carbon dioxide in the atmosphere. Variations depend on location and pollution levels, with pH potentially reaching 8.5 in some areas.
A pH above 7 is unexpectedly high for rainwater, suggesting potential contamination during collection — or that the samples were not rainwater but groundwater.