"Paraquat pot"

"Paraquat pot"

During the late 1970s, a controversial program sponsored by the US government sprayed paraquat on marijuana fields in Mexico.^[8] Since much of this marijuana was subsequently smoked by Americans, the US government's "Paraquat Pot" program stirred much debate. Perhaps in an attempt to deter people from using marijuana, representatives of the program warned that spraying rendered the crop unsafe to smoke.
However, independent bodies have studied paraquat in this use. Jenny Pronczuk de Garbino,^[9] stated: "no lung or other injury in marijuana users has ever been attributed to paraquat contamination". Also a United States Environmental Protection Agency manual states: "... toxic effects caused by this mechanism have been either very rare or nonexistent. Most paraquat that contaminates marijuana is pyrolyzed during smoking to dipyridyl, which is a product of combustion of the leaf material itself (including marijuana) and presents little toxic hazard."^[10]

[edit] In suicide

A large majority (93%) of fatalities from paraquat poisoning are cases of intentional self-administration, i.e., suicides. In third world countries, paraquat is a "major suicide agent".^[11] For instance, in Samoa from 1979-2001, 70% of suicides were by paraquat poisoning. In southern Trinidad from 1996-1997, 76% of suicides were by paraquat.^[12]
The reason paraquat is such a widely used suicide agent in third-world countries is due to its widespread availability, low toxic dose (10 ml or 2 teaspoons is enough to kill) and relative low cost. There are campaigns to control or even ban paraquat outright, and there are moves to restrict its availability by requiring user education and the locking up of paraquat stores.

[edit] Toxicity

Pure paraquat, when ingested, is highly toxic to mammals, including humans; potentially leading to acute respiratory distress syndrome (ARDS), and there are no specific antidotes. However, fuller's earth or activated charcoal is an effective treatment, if taken in time. Death may occur up to 30 days after ingestion. Diluted paraquat used for spraying is less toxic; thus, the greatest risk of accidental poisoning is during mixing and loading paraquat for use.^[3]

In acute toxicity studies using laboratory animals, paraquat has been shown to be highly toxic by the inhalation route and has been placed in Toxicity Category I (the highest of four levels) for acute inhalation effects. However, the EPA has determined that particles used in agricultural practices (400 to 800 μm) are well beyond the respirable range and therefore inhalation toxicity is not a toxicological endpoint of concern. Paraquat is toxic (Category II) by the oral route and moderately toxic (Category III) by the dermal route. Paraquat will cause moderate to severe eye irritation and minimal dermal irritation, and has been placed in Toxicity Categories II and IV (slightly toxic) respectively for these effects.^[13]

Even a single swig, immediately spat out, can cause death from fibrous tissue developing in the lungs, leading to asphyxiation.^[14]
According to the Center for Disease Control, ingesting paraquat causes symptoms such as liver, lung, heart, and kidney failure within several days to several weeks that can lead to death up to 30 days after ingestion. Those who suffer large exposures are unlikely to survive. Chronic exposure can lead to lung damage, kidney failure, heart failure, and oesophageal strictures.^[15] Accidental deaths and suicides from paraquat ingestion are relatively common. For example, there have been 18 deaths in Australia from paraquat poisoning since 2000.^[16]
Paraquat-induced toxicity in rats has also been linked to Parkinson's-like neurological degenerative mechanisms.^[17] A study by the Buck Institute showed a connection between exposure to paraquat and iron in infancy and mid-life Parkinson's in laboratory mice.^[18]
Long term exposures to paraquat would most likely cause lung and eye damage, but reproductive/fertility damage was not found by the EPA in their review. Some suspect a possible link to a greater incidence of Parkinson's disease.

Base (chemistry)(cocaine)

Base (chemistry)

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Acids and bases
Acid dissociation constant Acid-base extraction Acid-base reaction Dissociation constant Acidity function Buffer solutions pH Proton affinity Self-ionization of water
Acid types
Brønsted · Lewis · Mineral Organic · Strong Superacids · Weak
Base types
Brønsted · Lewis · Organic Strong · Superbases Non-nucleophilic · Weak
v • d • e

A base in chemistry is an aqueous substance that can accept hydronium ions. Bases are also the oxides or hydroxides of metals. A soluble base is also often referred to as an alkali if hydroxide ions (OH⁻) are involved. This refers to the Brønsted-Lowry theory of acids and bases. Alternative definitions of bases include electron pair donors (Lewis)^[1], and as sources of hydroxide anions (Arrhenius).^[2] In addition to this, bases can commonly be thought of as any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion activity lower than that of pure water, i.e. a pH higher than 7.0 at standard conditions. Examples of common bases are sodium hydroxide and ammonia. Type of solution that has a surplus of OH- ions.
Bases can be thought of as the chemical opposite of acids. A reaction between an acid and base is called neutralization. Bases and acids are seen as opposites because the effect of an acid is to increase the hydronium ion (H₃O⁺) concentration in water, whereas bases reduce this concentration. Bases react with acids to produce water and salts (or their solutions).

Contents [show] 1 Definitions 2 Properties 3 Bases and pH 4 Neutralization of acids 5 Alkalinity of non-hydroxides 6 Strong bases 6.1 Superbases 7 Bases as catalysts 8 See also 9 References

[edit] Definitions

Main article: acid-base reaction theories

A strong base is a base which hydrolyzes completely, raising the pH of the solution toward 14. Concentrated bases, like Concentrated acids, attack living tissue and cause serious burns. They react differently to skin than acids do, so while strong acids are corrosive, strong bases are referred to as caustic. Superbases are a class of especially basic compounds and non-nucleophilic bases are a special class of strong bases with poor nucleophilicity. Bases may also be weak bases such as ammonia, which is used for cleaning. Arrhenius bases are water-soluble and these solutions always have a pH greater than 7. An alkali is a special example of a base, where in an aqueous environment, hydroxide ions are donated. There are other more generalized and advanced definitions of acids and bases.
The notion of a base as a concept in chemistry was first introduced by the French chemist Guillaume François Rouelle in 1754. He noted that acids, which in those days were mostly volatile liquids (like acetic acid), turned into solid salts only when combined with specific substances. Rouelle considered that such a substance serves as a base for the salt, giving the salt a "concrete or solid form”.^[3]

Forms of cocaine

Salts

Cocaine, like many alkaloids can form many different salts, such as hydrochloride (HCl) and sulfate (-SO₄). Different salts have different solvency in solvents. Its hydrochloride, like many alkaloid hydrochloride is polar and is soluble in water.

Basic

Main article: Freebase (chemistry)

As the name implies, “freebase” is the base form of cocaine, as opposed to the salt form. It is practically insoluble in water whereas hydrochloride salt is water soluble.
Smoking freebase cocaine has the additional effect of releasing methylecgonidine into the user's system due to the pyrolysis of the substance (a side effect which insufflating or injecting powder cocaine does not create). Some research suggests that smoking freebase cocaine can be even more cardiotoxic than other routes of administration^[38] because of methylecgonidine's effects on lung tissue^[39] and liver tissue.^[40]
Pure cocaine is prepared by neutralizing its compounding salt with an alkaline solution which will precipitate to non-polar basic cocaine. It is further refined through aqueous-solvent Liquid-liquid extraction.

Forms of cocaine

Salts

Cocaine, like many alkaloids can form many different salts, such as hydrochloride (HCl) and sulfate (-SO₄). Different salts have different solvency in solvents. Its hydrochloride, like many alkaloid hydrochloride is polar and is soluble in water.

Basic

Main article: Freebase (chemistry)

As the name implies, “freebase” is the base form of cocaine, as opposed to the salt form. It is practically insoluble in water whereas hydrochloride salt is water soluble.

Smoking freebase cocaine has the additional effect of releasing methylecgonidine into the user's system due to the pyrolysis of the substance (a side effect which insufflating or injecting powder cocaine does not create). Some research suggests that smoking freebase cocaine can be even more cardiotoxic than other routes of administration^[38] because of methylecgonidine's effects on lung tissue^[39] and liver tissue.^[40]
Pure cocaine is prepared by neutralizing its compounding salt with an alkaline solution which will precipitate to non-polar basic cocaine. It is further refined through aqueous-solvent Liquid-liquid extraction.

Crack cocaine

Crack is a lower purity form of free-base cocaine and contains sodium bicarbonate as impurity. Freebase and crack are often administered by smoking.^[41] The origin of the name is from the crackling sound (hence the onomatopoeic “crack”) produced when cocaine containing impurities are heated.^[42]