Cannabis users perceptions of differences between hydro and bush weed

Introduction
According to the 2012 13 Illicit Drug Data Report, cannabis continues to be the most widely produced and used illicit drug in Australia, with the number of national cannabis seizures and arrests the highest recorded in the last decade (ACC 2014). There is widespread concern over the impact that increased potency and potential contamination of cannabis may have on the health of users (McLaren et al 2008; NCPIC 2011; Swift et al 2013). Given the prevalence of cannabis use, it is important that the harms associated with its use, and factors that may exacerbate such harms, are understood. The way in which cannabis is cultivated, stored and used can, intentionally or unintentionally, influence potency levels and provide avenues of contamination (NCPIC 2011, 2013). Few studies have explored potency levels for cannabis cultivated through different methods in Australia. In addition, the presence or lack of cannabis contamination in Australia remains unknown. In this paper, police detainees perceptions of intoxication effects, visual appearance and smell for different types of cultivated cannabis are examined, with a particular focus on potency and contamination.

While cannabis is produced, distributed and consumed in a range of different forms, there are two main types available on the Australian illicit drug market indoor-cultivated hydroponic (hydro) cannabis and outdoor-cultivated (bush) cannabis. In Australia, cannabis tends to be domestically produced (ACC 2014), with indoor-cultivated hydroponic cannabis being the most common (Stafford & Burns 2013; Willis 2008). Driving growers preference for indoor cultivation may be crop potency and yield gains that can be made through control of the growing environment (such as, light, humidity and temperature), year-round cultivation and the practice of cloning superior varieties (McLaren et al. 2008). There may also be greater opportunity, over outdoor growing techniques, to avoid law enforcement detection (Willis 2008). However, it is possible that differences in potency, between indoor and outdoor-cultivated cannabis, may not be as apparent in Australia (compared with countries experiencing colder climates such as that Northern Europe), due to the climate in many areas of Australia presenting ideal growing conditions (i.e., hotter and drier) (Potter 2010).

Introduction
According to the 2012 13 Illicit Drug Data Report, cannabis continues to be the most widely produced and used illicit drug in Australia, with the number of national cannabis seizures and arrests the highest recorded in the last decade (ACC 2014). There is widespread concern over the impact that increased potency and potential contamination of cannabis may have on the health of users (McLaren et al 2008; NCPIC 2011; Swift et al 2013). Given the prevalence of cannabis use, it is important that the harms associated with its use, and factors that may exacerbate such harms, are understood. The way in which cannabis is cultivated, stored and used can, intentionally or unintentionally, influence potency levels and provide avenues of contamination (NCPIC 2011, 2013). Few studies have explored potency levels for cannabis cultivated through different methods in Australia. In addition, the presence or lack of cannabis contamination in Australia remains unknown. In this paper, police detainees perceptions of intoxication effects, visual appearance and smell for different types of cultivated cannabis are examined, with a particular focus on potency and contamination.

While cannabis is produced, distributed and consumed in a range of different forms, there are two main types available on the Australian illicit drug market indoor-cultivated hydroponic (hydro) cannabis and outdoor-cultivated (bush) cannabis. In Australia, cannabis tends to be domestically produced (ACC 2014), with indoor-cultivated hydroponic cannabis being the most common (Stafford & Burns 2013; Willis 2008). Driving growers preference for indoor cultivation may be crop potency and yield gains that can be made through control of the growing environment (such as, light, humidity and temperature), year-round cultivation and the practice of cloning superior varieties (McLaren et al. 2008). There may also be greater opportunity, over outdoor growing techniques, to avoid law enforcement detection (Willis 2008). However, it is possible that differences in potency, between indoor and outdoor-cultivated cannabis, may not be as apparent in Australia (compared with countries experiencing colder climates such as that Northern Europe), due to the climate in many areas of Australia presenting ideal growing conditions (i.e., hotter and drier) (Potter 2010).

A 2013 analysis of potency levels of 26 cannabis samples taken from NSW police crop seizures showed no significant difference in the Delta-9-Tetrahydrocannabinol (THC) content between cannabis seized from indoor compared with outdoor cultivation sites (Swift et al. 2013). In contrast to this, Stafford and Burns (2013) found that 58 percent, of a nationally representative sample of regular injecting drug users, reported the potency of indoor-cultivated hydroponic cannabis as high, whereas only 20 percent rated outdoor-cultivated cannabis, bush weed , as of high potency. In addition to cultivation method, potency of cannabis may be affected by plant variety, the proportion of different parts of the plant present in the product (in descending order of potency buds (flowering heads), leaves stems and seeds) and storage (NCPIC 2013). Appearance of the cannabis product may provide an indication of its potency.
Perceived contamination may also guide user preference for indoor-cultivated hydroponic or outdoor-cultivated cannabis, with indoor-cultivated hydroponic cannabis often perceived to present a greater risk of contamination (StollzNow 2006). Potential sources of contamination may include actions taken by the grower to improve the appearance of the product or to bulk up weight (McLaren et al. 2008). For example, in 2007, the Department of Health in the United Kingdom issued a public health alert in response to the presence of grit weed , cannabis that had been contaminated with glass beads, on the market (DHSSPS 2007). Other potential sources of contamination may arise during the growing process from insecticides, fungi, bacteria and heavy metals in the soil (Decorte 2010). The perception that indoor-grown hydroponic cannabis is more susceptive to contamination, than cannabis grown outdoors, may, in part, reflect the belief that cannabis grown outdoors using organic methods (e.g., in soil and under natural light) is nature s way and therefore, is more pure (i.e., not mixed with contaminating substances, Potter 2010). This perception may not be indicative of the objective risk of harm.

Aims of study
In collaboration with the National Cannabis Prevention and Information Centre (NCPIC), the Australian Institute of Criminology (AIC) interviewed a sample of police detainees from across Australia to investigate their firsthand knowledge of, and experience using, indoor-cultivated hydroponic cannabis versus outdoor-cultivated cannabis. As contamination and increased potency are associated with increased health risks for users, it is of interest to determine whether there are perceived differences between the two types of cannabis in terms of intoxication effect, visual appearance and smell.
Specifically, the study aims to examine the following questions:
Is there a difference reported in potency or intoxication effects experienced as a result of consumption of indoor-cultivated hydroponic cannabis compared with outdoor-cultivated cannabis?
Are there differences in the visual appearance and smell of indoor-cultivated hydroponic cannabis, compared with outdoor-cultivated cannabis? Could any reported differences in visual appearance or smell be suggestive of potency and/or the presence of contamination?

Method
Data for this study were obtained from the AIC s Drug Use Monitoring in Australia (DUMA) database. The DUMA program uses an interviewer assisted self-report questionnaire to explore drug use and criminal justice-related issues. Detainees (or alleged offenders) at police stations and watchhouses across Australia are invited to participate; participation is voluntary. The DUMA survey is comprised of two components: a core questionnaire and a quarterly addendum. For further information on DUMA and its methodology, please see the most recent DUMA monitoring report by Sweeney and Payne (2012).
The current study is based on data collected during January and February 2012 at eight sites across Australia Adelaide (South Australia); Bankstown and Kings Cross (New South Wales); Brisbane and Southport (Queensland); Darwin (Northern Territory); East Perth (Western Australia); and Footscray (Victoria). The AIC, in consultation with NCPIC, designed an addendum questionnaire, which asked detainees whether there was a difference between indoor-cultivated hydroponic cannabis and outdoor-cultivated cannabis for each of the following categories intoxication effects, visual appearance and smell. If a detainee responded with yes to there being a difference, they were asked to specify the nature of that difference; participants could detail only one difference per item. Qualitative descriptions provided by detainees were categorised and coded.
To aid detainee understanding of the survey items, the colloquial terms hydro and bush weed were used to refer to indoor-cultivated hydroponic cannabis and outdoor-cultivated cannabis respectively. Hydro typically refers to cannabis grown indoors using a hydroponic system that involves pumping water and nutrient-rich solutions into the cannabis plant. Bush weed typically refers to cannabis grown outdoors in a more natural environment.

Results
Prevalence of cannabis use among police detainees
A total of 871 adult detainees (i.e., aged 18 years and over) participated in the addendum questionnaire, of these almost half (n=395; 45%) reported use of cannabis in the past 30 days. Table 1 shows the number and percentage of recent users of cannabis by the type of cannabis last used. The data are further broken down by site location. Comparison across sites cannot be made as the number of detainees interviewed per site varies considerably. Of the 364 respondents who identified the type of cannabis last used, the vast majority last used hydro (80%), 14 percent reported using bush and one percent reported hash use.

Table 1: Cannabis users, by cannabis type last used and DUMA site location

a: Hash (or hashish) is made from the resin (or secreted gum) of the cannabis plant. It is dried and pressed into small blocks and smoked.
b: Other type of cannabis includes mixes of bush/hydro/hash,
c: Only 364 of 395 recent users of cannabis specified the type of cannabis last used.
Excludes missing data .
Percentages may not total 100 due to rounding.
Source: AIC DUMA collection 2012 [Computer file].

Intoxication Effects
A total of 392 recent users of cannabis were asked whether there was a difference between hydro and bush weed in effects or the way it feels after smoking it 278 (71%) reported that there was a difference, 69 (18%) reported no difference and 45 (12%) did not know whether there was a difference.
Table 2 presents the number and percentage of detainees reporting differences in intoxication effects between hydro and bush weed. The largest proportion reported that hydro has a stronger effect (50%), compared with only one percent who reported that bush weed has a stronger effect. Eleven percent of detainees reported that the effects of bush last longer, compared with only three percent reporting that the effects of hydro last longer. In terms of the subjective experience of intoxication, six percent reported that bush weed has a more relaxing effect, with only one percent reporting the opposite (i.e., that hydro has a more relaxing effect). Thirteen percent of respondents reported that hydro gives a head stone and/or that bush weed gives a body stone . A small number of respondents elaborated on these terms, suggesting that head stone refers to effects that are felt in the mind and that can cause a user to trip out or become paranoid, and that body stone refers to the body feeling relaxed and lethargic.

Table 2. Perceived differences in intoxication effects of hydro and bush weed

Only one response allowed per detainee.
Percentages do not total 100 due to rounding.
Source: AIC DUMA collection 2012 [Computer file].

Visual appearance and smell
A total of 393 recent users of cannabis were asked whether there was a difference between hydro and bush weed in visual appearance and smell 300 (76%) reported that there was a difference in visual appearance, 292 (74%) reported that there was a difference in smell, 38 (10%) reported no difference in either visual appearance or smell, and 38 (10%) did not know whether there was a difference in either visual appearance or smell.

Visual appearance
Table 3 shows the number and percentage of detainees reporting differences in visual appearance between hydro and bush weed. In terms of texture, the most commonly reported difference was that hydro is stickier, more dense or more compact (26%), followed by bush weed is leafier (18%) and bush weed is drier or fluffier (8%). A number of detainees reported that hydro has more crystals compared with bush weed (6%). In terms of colour, bush weed was reported as darker or greener than hydro by ten percent of detainees, while five percent of detainees reported the opposite to be true (i.e., hydro is darker/greener than bush weed). A further eight percent of detainees reported that hydro is brighter or lighter than bush weed.

Table 3. Perceived differences in visual appearance of hydro and bush weed

Only one response allowed per detainee.
Percentages do not total 100 due to rounding.
Source: AIC DUMA collection 2012 [Computer file].

Smell
Table 4 displays the number and percentage of detainees reporting differences in smell between hydro and bush weed. The majority of detainees reported that hydro has a stronger smell (63%), compared with only three percent who believed the opposite to be true (i.e, that bush has a stronger smell). Eleven percent of detainees reported than hydro has a more chemical smell. Consistent with this, nine percent of detainees reported that bush weed has a more natural smell.

Table 4: Perceived differences in smell of hydro and bush weed

Only one response allowed per detainee.
Source: AIC DUMA collection 2012 [Computer file].

Discussion
Differences between indoor-cultivated cannabis hydro and outdoor-cultivated cannabis bush weed were reported by the majority of cannabis-using police detainees. There was a level of disagreement among detainees as to the specific nature of differences between hydro and bush weed , with a minority of detainees reporting that there were no differences or that they did not know whether there were differences. This suggests that there may not be a clear distinction between the two cannabis types, in terms of intoxication effects, appearance and smell. Alternatively, it may indicate that cannabis product, when sold, may not accurately depict the method of cultivation. Consistent with this explanation, sixteen percent of the sample reported that they had obtained cannabis that turned out to be different to what was expected, with differences in cultivation, strain, effect and quality reported. Another explanation may be that inexperienced users lack the knowledge needed to determine cannabis type, and therefore, may be more susceptible to receiving misinformation from dealers.

Of detainees who had recently used cannabis, the vast majority reported using hydro on their last occasion of use. This finding is consistent with the prominence of use of hydro over bush weed reported in other studies of Australian cannabis users (e.g., Stafford & Burns 2013). The high rates of hydro use may reflect a user preference or a higher level of availability of indoor-cultivated hydroponic cannabis on the Australian illicit drug market. The availability of both types of cannabis (hydro and bush weed) is generally considered very easy or easy to obtain (Stafford & Burns 2013). Although, some cannabis users report hydro to be more readily available than bush weed in some jurisdictions in Australia (Stafford & Burns 2013). Further research is needed to determine the reasons behind grower preference for cultivation method and the processes that growers employ to maximise crop yield.

In terms of intoxication effects, users most commonly reported that indoor-cultivated hydroponic cannabis has a stronger effect than outdoor-cultivated cannabis. This is in contrast to Swift and colleagues 2013 finding, which reported that there was no significant difference in the cannabinoid content between indoor and outdoor crops, based on a comparison of NSW police cannabis crop seizures. The difference reported by users may reflect user expectancy; in that they expect hydro to be more potent and so perceive it to be so. On the other hand, it may be that potency differences are not present in the cannabis plant themselves, but are present in the resulting product marketed to users. For example, the ratio of specific parts of the plant or substances added during preparation for sale may influence potency and differ between cannabis products marketed as hydro and bush weed cannabis. Testing of cannabis crops with known cultivation techniques, as well as the resulting product received by users, is needed to understand the impact of cultivation techniques and the processes undertaken to ready the product for sale on the potency of the resulting cannabis product.

Based on detainee reports, indoor-hydroponic cannabis is stickier, denser, more compact and contains more crystals , whereas outdoor-grown cannabis is drier and fluffier. Without examining the cannabis product, it is difficult to determine whether visual appearances are indicative of potency or contamination. Crystals may refer to the resinous trichomes commonly found on the flowering head and surrounding leaves of the cannabis plant, which contain high levels of cannabinoids. Crystals may also refer to chemicals or other substances added to the cannabis product to mimic the appearance of greater potency (Decorte 2011). To date, there have been no official reports of synthetic crystals being added to cannabis products in Australia, and so it is likely that detainee reports of the presence of crystals in hydro cannabis may reflect a higher presence of the flowering head of the plant.

Limitations
The findings in this paper should be interpreted in light of the following limitations. First, although hydroponic cannabis is typically grown indoors, it is possible that the term hydro may have included indoor and outdoor-cultivated hydroponic cannabis. Second, it is possible that the prevalence of perceived differences between hydro and bush cannabis was restricted by detainees specifying only one difference per category (i.e., intoxication effects, visual appearance and smell).

Conclusion
Systematic testing of cannabis crops with known cultivation methods, as well as the subsequent product received by users, is needed to determine the impact of cultivation methods on potency and contamination of cannabis products consumed in Australia. Monitoring user perceptions of cannabis quality, in conjunction with cannabis testing, can provide valuable insight into the nature of and changes to cannabis products on the Australian illicit drug market.

References
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