Drug markets have changed considerably since the 1980s; greater
competition, and a shift from highly structured (and thus controlled) to
greatly fragmented markets, has generated competition among dealers in
terms of purity.
Many drugs that reach the street are now only cut at the manufacture/producer stage, and this may be more a matter of lacing the drug with another
substance designed to appeal to the consumer, as opposed to simple diluents that increase the profit for the seller. The extent of cutting can vary significantly over time but for the last 15 years drugs such as heroin and cocaine have often sat at the 50% purity level.
Heroin purity sitting at 50% does not mean 50% cutting agents, other adulterants could include other opiate by-products of making heroin from opium.
Coomber (1997d), after having street heroin seizures from the UK re-analysed, reported that nearly 50% of the samples had no cutting agents present at all. This means that 50% of street heroin in the UK in 1995 had worked its way from producer to user without being cut at any stage, although other adulterants may have been present.
Other research by Coomber (1997b) outlined how drug dealers have other ways of making profit without having to resort to cutting the drugs they sell.
Cocaine has been cut with various substances ranging from flour and powdered milk to ground drywall, rat poison, and battery acid.
Most hard drugs are adulterated to some degree. Some street drugs can be as low as 10-15% of the active drug, with the other (85-90%) not necessarily being the cutting agent. In fact a heroin sample of only 20% purity may have no cutting agents in it at all. The other 80% may be impurities produced in the manufacturing process and substances created as by products of this process and/or degradation of the drug if improperly stored.
When choosing a cutting agent, the drug manufacturer or dealer would ideally attempt to find a chemical that is inexpensive, easy to obtain, relatively non-toxic, and mimics the physical attributes of the drug to be adulterated. For example, if a drug is soluble in water, the preferred adulterant would also be water-soluble. Similar melting and boiling points are also important if the drug is to be smoked.
Despite cannabis being generally perceived as a natural or "chemical-free" product,[71] in a recent Australian survey[72] one in four Australians consider cannabis grown indoors under hydroponic conditions to be a greater health risk due to increased contamination, added to the plant during cultivation to enhance the plant growth and quality.
Cannabis also has been shown to have a synergistic cytotoxic effect on lung cancer cell cultures in vitro with the food additive butylated hydroxyanisole (BHA) and possibly the related compound butylated hydroxytoluene (BHT). The study concluded, "Exposure to marijuana smoke in conjunction with BHA, a common food additive, may promote deleterious health effects in the lung." BHA & BHT are human-made fat preservatives, and are found in many packaged foods including: plastics in boxed cereal, Jello, Slim Jims, and more.[75][further explanation needed]
The Australian National Household Survey of 2001[76] showed that cannabis use in Australia is rarely used without other drugs. 95% of cannabis users also drank alcohol; 26% took amphetamines; 19% took ecstasy and only 2.7% reported not having used any other drug with cannabis.[77] While research has been undertaken on the combined effects of alcohol and cannabis on performing certain tasks, little research has been conducted on the reasons why this combination is so popular. Evidence from a controlled experimental study undertaken by Lukas and Orozco[78] suggests that alcohol causes THC to be absorbed more rapidly into the blood plasma of the user. Data from the Australian National Survey of Mental Health and Wellbeing[79] found that three-quarters of recent cannabis users reported using alcohol when cannabis was not available.[80]
In a 2001 study looking at neuropsychological performance in long-term cannabis users, researchers found "some cognitive deficits appear detectable at least 7 days after heavy cannabis use but appear reversible and related to recent cannabis exposure rather than irreversible and related to cumulative lifetime use".[82] On his studies regarding cannabis use, lead researcher and Harvard professor Harrison Pope said he found marijuana is not dangerous over the long term, but there are short-term effects. From neuropsychological tests, Pope found that chronic cannabis users showed difficulties, with verbal memory in particular, for "at least a week or two" after they stopped smoking. Within 28 days, memory problems vanished and the subjects “were no longer distinguishable from the comparison group”.[83]
Researchers from the University of California, San Diego School of Medicine failed to show substantial, systemic neurological effects from long-term recreational use of cannabis. Their findings were published in the July 2003 issue of the Journal of the International Neuropsychological Society.[84] The research team, headed by Dr Igor Grant, found that cannabis use did affect perception, but did not cause permanent brain damage. Researchers looked at data from 15 previously published controlled studies involving 704 long-term cannabis users and 484 nonusers. The results showed long-term cannabis use was only marginally harmful on the memory and learning. Other functions such as reaction time, attention, language, reasoning ability, perceptual and motor skills were unaffected. The observed effects on memory and learning, they said, showed long-term cannabis use caused "selective memory defects", but that the impact was "of a very small magnitude".[85]
Endogenous cannabinoids (“endocannabinoids”) were discovered in cow's milk and soft cheeses.[90][91] Endocannabinoids were also found in human breast milk.[92] It is widely accepted that the neonatal survival of many species "is largely dependent upon their suckling behavior, or appetite for breast milk"[93] and recent research has identified the endogenous cannabinoid system to be the first neural system to display complete control over milk ingestion and neonatal survival.[94] It is possible that "cannabinoid receptors in our body interact with the cannabinoids in milk to stimulate a suckling response in newborns so as to prevent growth failure".[93]
More research is no guarantee of greater consensus in the field of cannabis studies, however; both advocates and opponents of the drug are able to call upon multiple scientific studies supporting their respective positions. Cannabis has been correlated with the development of various mental disorders in multiple studies, for example a recent 10 year study on 1,923 individuals from the general population in Germany, aged 14–24, concluded that cannabis use is a risk factor for the development of incident psychotic symptoms. Continued cannabis use might increase the risk for psychotic disorder.[97]
Efforts to prove the "gateway drug" hypothesis that cannabis and alcohol makes users more inclined to become addicted to "harder" drugs like cocaine and heroin have produced mixed results, with different studies finding varying degrees of correlation between the use of cannabis and other drugs, and some finding none. Some[who?], however, believe the "gateway effect," currently being pinned on the use of marijuana, should not be attributed to the drug itself but rather the illegality of the drug in most countries. Supporters of this theory[attribution needed] believe that the grouping of marijuana and harder drugs in law is, in fact, the cause of users of marijuana to move on to those harder drugs.
There have been debates as to whether cannabis can lead to heavy addiction. According to one of the studies on the issue, the La Guardia Committee of 1944, smoking marijuana could help to get out of the addiction from substances like cocaine or morphine.
Cannabis withdrawal is included in the proposed revision of DSM-5.[98][99][100] Several drugs have been investigated in an attempt to ameliorate the symptoms of cannabis withdrawal. Such drugs include bupropion, divalproex, nefazodone, lofexidine, and dronabinol. Of these, dronabinol has proven the most effective.[100]
Melanie Dreher, dean of nursing at Rush Medical Center in Chicago, conducted a study of Jamaican women who used cannabis throughout their pregnancies, as well as their babies' first year. The study was published in the American Journal of Pediatrics in 1994.[102] Dreher expected to see a decrease in birth weight, but saw none. Instead, the exposed babies socialized and made eye contact more quickly, had better organization and modulation of sleeping and waking, and were less prone to anxiety. On difference between the Jamaican and other studies' results, "Medicine hunter" Chris Kilham noted, "In U.S. studies where we've seen a similar investigation, women have concurrently been abusing alcohol and other drugs as well".[103]
Mold is also found in smoke from mold infected cannabis,[104][105] and the lungs and nasal passages are a major means of contracting fungal infections. Levitz and Diamond (1991) suggested baking marijuana in home ovens at 150 °C [302 °F], for five minutes before smoking. Oven treatment killed conidia of A. fumigatus, A. flavus and A. niger, and did not degrade the active component of marijuana, tetrahydrocannabinol (THC)."[104]
Drug bottle containing cannabis
In many countries, experimental science regarding cannabis is restricted due to its illegality.
Thus, cannabis as a drug is often hard to fit into the structural
confines of medical research because appropriate, research-grade samples
are difficult to obtain for research purposes, unless granted under
authority of national governments.
The cannabis that is available for research studies in the United States is grown at the University of Mississippi and solely controlled by the NIDA, which has veto power over the Food and Drug Administration (FDA) to define accepted protocols. Since 1942, when cannabis was removed from the U.S. Pharmacopoeia and its medical use was prohibited, there have been no legal (under federal law) privately funded cannabis production projects. This has resulted in a limited amount of research being done and possibly in NIDA producing cannabis which has been alleged to be of very low potency and inferior quality.[107]
MAPS, in conjunction with Professor Lyle Craker, PhD, the director of the Medicinal Plant Program at the University of Massachusetts Amherst, sought to provide independently grown cannabis of more appropriate research quality for FDA-approved research studies, and encountered opposition by NIDA, the ONDCP, and the U.S. Drug Enforcement Administration (DEA).
Many drugs that reach the street are now only cut at the manufacture/producer stage, and this may be more a matter of lacing the drug with another
substance designed to appeal to the consumer, as opposed to simple diluents that increase the profit for the seller. The extent of cutting can vary significantly over time but for the last 15 years drugs such as heroin and cocaine have often sat at the 50% purity level.
Heroin purity sitting at 50% does not mean 50% cutting agents, other adulterants could include other opiate by-products of making heroin from opium.
Coomber (1997d), after having street heroin seizures from the UK re-analysed, reported that nearly 50% of the samples had no cutting agents present at all. This means that 50% of street heroin in the UK in 1995 had worked its way from producer to user without being cut at any stage, although other adulterants may have been present.
Other research by Coomber (1997b) outlined how drug dealers have other ways of making profit without having to resort to cutting the drugs they sell.
Cocaine has been cut with various substances ranging from flour and powdered milk to ground drywall, rat poison, and battery acid.
Most hard drugs are adulterated to some degree. Some street drugs can be as low as 10-15% of the active drug, with the other (85-90%) not necessarily being the cutting agent. In fact a heroin sample of only 20% purity may have no cutting agents in it at all. The other 80% may be impurities produced in the manufacturing process and substances created as by products of this process and/or degradation of the drug if improperly stored.
When choosing a cutting agent, the drug manufacturer or dealer would ideally attempt to find a chemical that is inexpensive, easy to obtain, relatively non-toxic, and mimics the physical attributes of the drug to be adulterated. For example, if a drug is soluble in water, the preferred adulterant would also be water-soluble. Similar melting and boiling points are also important if the drug is to be smoked.
Adulterated cannabis
Contaminants may be found in hashish obtained from "soap bar"-type sources.[68] The dried flowers of the plant may be contaminated by the plant taking up heavy metals and other toxins from its growing environment,[69] or by the addition of lead or glass beads, used to increase the weight or to make the cannabis appear as if it has more crystal-looking trichomes indicating a higher THC content.[70] Users who burn hot or mix cannabis with tobacco are at risk of failing to detect deviations from appropriate cannabis taste.Despite cannabis being generally perceived as a natural or "chemical-free" product,[71] in a recent Australian survey[72] one in four Australians consider cannabis grown indoors under hydroponic conditions to be a greater health risk due to increased contamination, added to the plant during cultivation to enhance the plant growth and quality.
Combination with other drugs
The most obvious confounding factor in cannabis research is the prevalent usage of other recreational drugs, especially alcohol and nicotine.[73] Such complications demonstrate the need for studies on cannabis that have stronger controls, and investigations into alleged symptoms of cannabis use that may also be caused by tobacco. Some critics question whether agencies doing the research make an honest effort to present an accurate, unbiased summary of the evidence, or whether they "cherry-pick" their data to please funding sources which may include the tobacco industry or governments dependent on cigarette tax revenue; others caution that the raw data, and not the final conclusions, are what should be examined.[74]Cannabis also has been shown to have a synergistic cytotoxic effect on lung cancer cell cultures in vitro with the food additive butylated hydroxyanisole (BHA) and possibly the related compound butylated hydroxytoluene (BHT). The study concluded, "Exposure to marijuana smoke in conjunction with BHA, a common food additive, may promote deleterious health effects in the lung." BHA & BHT are human-made fat preservatives, and are found in many packaged foods including: plastics in boxed cereal, Jello, Slim Jims, and more.[75][further explanation needed]
The Australian National Household Survey of 2001[76] showed that cannabis use in Australia is rarely used without other drugs. 95% of cannabis users also drank alcohol; 26% took amphetamines; 19% took ecstasy and only 2.7% reported not having used any other drug with cannabis.[77] While research has been undertaken on the combined effects of alcohol and cannabis on performing certain tasks, little research has been conducted on the reasons why this combination is so popular. Evidence from a controlled experimental study undertaken by Lukas and Orozco[78] suggests that alcohol causes THC to be absorbed more rapidly into the blood plasma of the user. Data from the Australian National Survey of Mental Health and Wellbeing[79] found that three-quarters of recent cannabis users reported using alcohol when cannabis was not available.[80]
Memory and learning
Studies on cannabis and memory are hindered by small sample sizes, confounding drug use, and other factors.[81] The strongest evidence regarding cannabis and memory focuses on its temporary negative effects on short-term and working memory.[11]In a 2001 study looking at neuropsychological performance in long-term cannabis users, researchers found "some cognitive deficits appear detectable at least 7 days after heavy cannabis use but appear reversible and related to recent cannabis exposure rather than irreversible and related to cumulative lifetime use".[82] On his studies regarding cannabis use, lead researcher and Harvard professor Harrison Pope said he found marijuana is not dangerous over the long term, but there are short-term effects. From neuropsychological tests, Pope found that chronic cannabis users showed difficulties, with verbal memory in particular, for "at least a week or two" after they stopped smoking. Within 28 days, memory problems vanished and the subjects “were no longer distinguishable from the comparison group”.[83]
Researchers from the University of California, San Diego School of Medicine failed to show substantial, systemic neurological effects from long-term recreational use of cannabis. Their findings were published in the July 2003 issue of the Journal of the International Neuropsychological Society.[84] The research team, headed by Dr Igor Grant, found that cannabis use did affect perception, but did not cause permanent brain damage. Researchers looked at data from 15 previously published controlled studies involving 704 long-term cannabis users and 484 nonusers. The results showed long-term cannabis use was only marginally harmful on the memory and learning. Other functions such as reaction time, attention, language, reasoning ability, perceptual and motor skills were unaffected. The observed effects on memory and learning, they said, showed long-term cannabis use caused "selective memory defects", but that the impact was "of a very small magnitude".[85]
Appetite
The feeling of increased appetite following the use of cannabis has been documented for hundreds of years,[86] and is known as "the munchies" in popular culture. Clinical studies and survey data have found that cannabis increases food enjoyment and interest in food.[87][88] Scientists have claimed to be able to explain what causes the increase in appetite, concluding that "endocannabinoids in the hypothalamus activate cannabinoid receptors that are responsible for maintaining food intake".[88] Rarely, chronic users experience a severe vomiting disorder, cannabinoid hyperemesis syndrome, after smoking and find relief by taking hot baths.[89]Endogenous cannabinoids (“endocannabinoids”) were discovered in cow's milk and soft cheeses.[90][91] Endocannabinoids were also found in human breast milk.[92] It is widely accepted that the neonatal survival of many species "is largely dependent upon their suckling behavior, or appetite for breast milk"[93] and recent research has identified the endogenous cannabinoid system to be the first neural system to display complete control over milk ingestion and neonatal survival.[94] It is possible that "cannabinoid receptors in our body interact with the cannabinoids in milk to stimulate a suckling response in newborns so as to prevent growth failure".[93]
Long-term effects
Main article: Long-term effects of cannabis
Though the long-term effects of cannabis have been studied, there
remains much to be concluded; debated topics include the drug's
addictiveness, its potential as a "gateway drug", its effects on
intelligence and memory, and its contributions to mental disorders such
as schizophrenia and depression. On some such topics, such as the drug's
effects on the lungs, relatively little research has been conducted,
leading to division as to the severity of its impact. However, a study
funded by the US government on the long term lung-related effects of
marijuana has concluded that moderate marijuana use does not impair
pulmonary function.[95][96]More research is no guarantee of greater consensus in the field of cannabis studies, however; both advocates and opponents of the drug are able to call upon multiple scientific studies supporting their respective positions. Cannabis has been correlated with the development of various mental disorders in multiple studies, for example a recent 10 year study on 1,923 individuals from the general population in Germany, aged 14–24, concluded that cannabis use is a risk factor for the development of incident psychotic symptoms. Continued cannabis use might increase the risk for psychotic disorder.[97]
Efforts to prove the "gateway drug" hypothesis that cannabis and alcohol makes users more inclined to become addicted to "harder" drugs like cocaine and heroin have produced mixed results, with different studies finding varying degrees of correlation between the use of cannabis and other drugs, and some finding none. Some[who?], however, believe the "gateway effect," currently being pinned on the use of marijuana, should not be attributed to the drug itself but rather the illegality of the drug in most countries. Supporters of this theory[attribution needed] believe that the grouping of marijuana and harder drugs in law is, in fact, the cause of users of marijuana to move on to those harder drugs.
There have been debates as to whether cannabis can lead to heavy addiction. According to one of the studies on the issue, the La Guardia Committee of 1944, smoking marijuana could help to get out of the addiction from substances like cocaine or morphine.
Cannabis withdrawal is included in the proposed revision of DSM-5.[98][99][100] Several drugs have been investigated in an attempt to ameliorate the symptoms of cannabis withdrawal. Such drugs include bupropion, divalproex, nefazodone, lofexidine, and dronabinol. Of these, dronabinol has proven the most effective.[100]
Effects in pregnancy
A study of 600 mothers that reported smoking cannabis during pregnancy suggested that it was not associated with increased risk of perinatal mortality.[101] However, frequent and regular use of cannabis throughout pregnancy may be associated with a small but statistically detectable decrease in birth weight.[101]Melanie Dreher, dean of nursing at Rush Medical Center in Chicago, conducted a study of Jamaican women who used cannabis throughout their pregnancies, as well as their babies' first year. The study was published in the American Journal of Pediatrics in 1994.[102] Dreher expected to see a decrease in birth weight, but saw none. Instead, the exposed babies socialized and made eye contact more quickly, had better organization and modulation of sleeping and waking, and were less prone to anxiety. On difference between the Jamaican and other studies' results, "Medicine hunter" Chris Kilham noted, "In U.S. studies where we've seen a similar investigation, women have concurrently been abusing alcohol and other drugs as well".[103]
Pathogens and microtoxins
Most microorganisms found in cannabis only affect plants and not humans, but some microorganisms, especially those that proliferate when the herb is not correctly dried and stored, can be harmful to humans. Some users may store marijuana in an airtight bag or jar in a refrigerator to prevent fungal and bacterial growth.[104]Fungi
The fungi Aspergillus flavus,[105] Aspergillus fumigatus,[105] Aspergillus niger,[105] Aspergillus parasiticus, Aspergillus tamarii, Aspergillus sulphureus, Aspergillus repens, Mucor hiemalis (not a human pathogen), Penicillium chrysogenum, Penicillium italicum and Rhizopus nigrans have been found in moldy cannabis.[104] Aspergillus mold species can infect the lungs via smoking or handling of infected cannabis and cause opportunistic and sometimes deadly aspergillosis.[citation needed] Some of the microorganisms found create aflatoxins, which are toxic and carcinogenic. Researchers suggest that moldy cannabis thus be discarded.[citation needed]
Mold is also found in smoke from mold infected cannabis,[104][105] and the lungs and nasal passages are a major means of contracting fungal infections. Levitz and Diamond (1991) suggested baking marijuana in home ovens at 150 °C [302 °F], for five minutes before smoking. Oven treatment killed conidia of A. fumigatus, A. flavus and A. niger, and did not degrade the active component of marijuana, tetrahydrocannabinol (THC)."[104]
Bacteria
Cannabis contaminated with Salmonella muenchen was positively correlated with dozens of cases of salmonellosis in 1981.[106] "Thermophilic actinomycetes" were also found in cannabis.[105]Constraints on open research
United States
This issue was highlighted in the United States by the clash between Multidisciplinary Association for Psychedelic Studies (MAPS), an independent research group, and the National Institute on Drug Abuse (NIDA), a federal agency charged with the application of science to the study of drug abuse. The NIDA largely operates under the general control of the Office of National Drug Control Policy (ONDCP), a White House office responsible for the direct coordination of all legal, legislative, scientific, social and political aspects of federal drug control policy.[citation needed]The cannabis that is available for research studies in the United States is grown at the University of Mississippi and solely controlled by the NIDA, which has veto power over the Food and Drug Administration (FDA) to define accepted protocols. Since 1942, when cannabis was removed from the U.S. Pharmacopoeia and its medical use was prohibited, there have been no legal (under federal law) privately funded cannabis production projects. This has resulted in a limited amount of research being done and possibly in NIDA producing cannabis which has been alleged to be of very low potency and inferior quality.[107]
MAPS, in conjunction with Professor Lyle Craker, PhD, the director of the Medicinal Plant Program at the University of Massachusetts Amherst, sought to provide independently grown cannabis of more appropriate research quality for FDA-approved research studies, and encountered opposition by NIDA, the ONDCP, and the U.S. Drug Enforcement Administration (DEA).
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