The Pituri Learning Circle : central Australian Aboriginal women ’ s knowledge and practices around the use of Nicotiana spp . as a chewing tobacco

Introduction: Tobacco smoking has a range of known and predictable adverse outcomes, and across the world sustained smoking reduction campaigns are targeted towards reducing individual and public risk and harm. Conversely, more than 87 million women, mostly in lowand middle-income countries, use smokeless tobacco, yet the research examining the effect of this form of tobacco exposure on women is remarkably scant. In central Australia, the chewing of wild Nicotiana spp., a tobacco plant, commonly known as pituri and mingkulpa, is practised by Aboriginal groups across a broad geographical area. Until recently, there had been no health research conducted on the effects of chewing pituri. Methods: This article reports on one component of a multidimensional pituri research agenda. A narrative approach utilising the methodology of the Learning Circle was used to interview three key senior central Australian Aboriginal women representative of three large geographical language groupings. The participants were selected by a regional Aboriginal women’s organisation. With the assistance of interpreters, a semistructured interview, and specific trigger resources, participants provided responses to enable an understanding of the women’s ethnobotanical pituri knowledge and practices around the use of pituri within the context of Aboriginal women’s lives. Data were transcribed, and by using a constant comparison analysis, emergent themes were categorised. The draft findings and manuscript were translated into the participants’ language and validated by the participants.


Introduction
The mastication of tobacco (Nicotiana spp.) and the retention of the tobacco quid on the lips and in the mouth for the purpose of nicotine extraction is recognised as a form of smokeless tobacco (SLT) use 1 .The Global Adult Tobacco Survey sample of 14 lowand middle-income countries demonstrated that this form of tobacco use is a common practice in Indigenous populations, with an estimated 87 million women in those countries aged ≥15 years using SLT 2 .In addition, in several industrialised countries, SLT use is increasing 3 .In the 350 000 km 2 area of southern and western central Australia, the chewing of wild tobacco plants, the Nicotiana spp., is a common practice 4 .A survey of Aboriginal people and SLT use in this region in 1986 reported 'most women … chew in central Australia' 5 .No broad contemporary usage data exist; however, 27% of Aboriginal participants in a wider program of research examining SLT use and pregnancy and birthing outcomes reported SLT use (Ratsch A., unpublished data).
Thirty years ago, the 1986 Surgeon's General report 6 articulated health concerns related to the use of SLT.Several country-specific research activities have examined the health consequences of SLT and specifically the effects of use during pregnancy 7 ; however, comparison of those data to the central Australian Aboriginal population's use of Nicotiana spp., both generally and specifically related to women, is hampered by the global variety of products described under the nomenclature of SLT, the differing production and curing methods of tobacco, the various tobacco formulations and admixtures, the differences in methods of tobacco administration, individual frequency and dose used, and the self-reported nature of use [1][2][3] .In addition, the research examining the use of Nicotiana spp. in central Australian Aboriginal populations is in the early stages of ascertaining botanicalpharmacological, demographic and health data.Given these limitations, comparisons of the health outcomes of chewing Australian Nicotiana spp. to other worldwide findings would be premature.
In establishing the larger research program of botanicalpharmacological, demographic and health data, it became clear that the non-Aboriginal understanding of the Aboriginal chewing substance known as pituri was vastly different from that of Aboriginal peoples.Accordingly, the research question of this article emerged: 'What do central Australian Aboriginal women understand about Nicotiana spp.?' The research has three aims: • to record and document Aboriginal women's ethnobotanical knowledge and practices related to pituri • to record and document Aboriginal women's ethnopharmacological knowledge and usage of pituri • to record and document pituri use in the social context of Aboriginal women's lives.

Nicotiana spp. and nicotine pharmacokinetics
In Australia, there are 22 native species and four subspecies of Nicotiana widespread across the continent (Fig1) 8 .The botanical plant (Nicotiana spp.) and the tobacco chew (quid) are commonly, and interchangeably, referred to as pituri and mingkulpa by both Aboriginal and non-Aboriginal central Australians.Nicotiana spp. is primarily an annual plant, with growth and new plants dependent upon rain.The alkaloid level of Nicotiana spp.varies with species and environmental conditions 4,8,9 .Nicotine is the major pharmacologically active alkaloid, with levels in field-grown Australian species ranging from 0.6 to 18.46 mg/g dry weight 10,11 .
Nicotine can exist as a free base or a salt.At higher pH levels, nicotine can readily cross cell membranes, including the oral/nasal, skin and respiratory surfaces, resulting in more rapid increases and higher concentrations of blood nicotine 9,12 .SLT is often modified commercially or by users (eg with slated lime) to achieve a higher pH 13 .Central Australian Aboriginal populations use similar pharmacokinetics to modify the pH of the pituri quid by the addition of wood ash obtained from specific trees.N. gossei has a pH of 5.47, and samples of the preferred wood ash demonstrate pH values of 12.2-13.2;when ash is added to N. gossei, the pH of the quid increases to 10.2-11.6 (N.Moghbel, personal  communication, 2015).Aboriginal people place the quid orally for mucosal absorption, and utilise other sites for transdermal absorption, most commonly behind the ear 4 .

Research development and research paradigm
People of the language groups of Ngaanyatjarra, Pitjantjatjara and Yankunytjatjara are recognised as having extensive knowledge related to pituri 4 and are able to provide perspectives on pituri use across broad geographical regions.Discussions had taken place over a 5 year period between Aboriginal and non-Aboriginal co-authors and a consultative group of 13 senior Aboriginal women representative of the three language groups.The consultative group, as senior knowledge holders, are key informants in terms of both pituri and women's health.
The notion that pituri is a tobacco plant was avidly rejected by the women from the outset.Similarly, the notion that chewing pituri could have adverse health consequences was unanimously contested and rebuffed.With rare exception, the consultative group were pituri chewers.They were unable to reconcile the Western knowledge with their own ethnobotanical knowledge and experiences, that knowledge also being that of their mothers and grandmothers and their daughters and granddaughters.However, the group conduct their activities from within their own well-established evidenced-based framework, which they term an 'Aboriginal approach to action research'.This framework enables the group to consider evidence within complex cultural and social paradigms and determine strategic directions that are relevant and contextualised to that domain.The consultative group requested evidence in the form of credible Aboriginal knowledge to align with the Aboriginal Action Research framework.
A literature review 14 revealed a dearth of credible pituri knowledge both in terms of general health and specifically related to women's health.Notably, there was an absence of Aboriginal women's voices in the literature.Accordingly, the research question 'What do central Australian Aboriginal women understand about Nicotiana spp.?' emerged and was advanced through the consultative group.The research objective was to contextualise Aboriginal women's ethnopharmacological understanding of Nicotiana spp. as pituri in parallel with non-Aboriginal ethnopharmacological understanding of Nicotiana spp., the outcomes of which could then be considered by the group within their Aboriginal Action Research framework.

Methodology
By utilising an adaptation of Riel's Learning Circle framework 15 , a research model was constructed (Fig2) where both the learning and the leadership would be distributed; no single person would be the expert with the final say on what was, or was not, the truth, and each member of the circle would be responsible for sharing their own knowledge.This methodology would enable the recognition of the discrete ancestral and cultural reality and knowledge of each Aboriginal participant in parallel with the non-Aboriginal participant's Western knowledge.
A research proposal for the conduct of face-to-face semistructured interviews was developed and approved by the consultative group.
Within the geographical area, 22 Aboriginal dialects are spoken, and initial attempts to interview the consultative group as a cohort were hampered by this complexity and the eagerness of each member to contribute.The consultative group determined that the best way forward was for them to select a participant from each major language group to represent their knowledge.The three members chosen were pituri users, all strong self-advocates, and were among those most vocal in challenging the Western knowledge of pituri as tobacco.Data gathering was undertaken in a venue owned by the participants, and culturally adapted and respectful ethical briefing was provided prior to commencement.The Aboriginal participants were reimbursed in accordance with the National Health and Medical Research Council recommended fees for research consultants 16 .The cultural security of the participants was of primary importance; however, each participant requested that their responses be attributed to them by name in this publication and acknowledged as their knowledge.The participants were (by alphabetic order of the women's organisation) Maimie Butler, Ngaanyatjarra; Janet Inyika, Pitjantjatjara; and Margaret Smith, Yankunytjatjara.The dialogue was conducted over 4 hours by AR (a non-Aboriginal, tertiary qualified, health practitioner) and AM (a remote Aboriginal, tertiary qualified, organisational leader) with at least one interpreter present at all times.The dialogue used the technique of 'yarning' advocated by several authors [17][18][19] as a method for successfully establishing, progressing and completing interviews with Aboriginal participants.
Resources to trigger discussion were provided by the Aboriginal participants and included: • personal supply of pituri and ash • pituri and ash demonstration • pituri oral and post-auricular placement demonstration • geographical maps of preferred pituri locations • pituri harvesting and preparation diagrams.
These were augmented by non-Aboriginal trigger resources: • 39 point semistructured interview schedule with 32 specifically focused enquiry points developed from observation, interactions with pituri users, and gaps in the literature • list of nicotine desirable and adverse effects • Nicotiana spp.laboratory and internet images • Nicotiana spp.nicotine and metabolite data.
The dialogue commenced by gathering participant demographics and then the enquiry points on the semistructured interview schedule were raised one at a time round the circle to each participant.Nicotiana spp.chemical analysis data were utilised as a trigger resource, as were laboratory and internet images.In response to the illustrative triggers, the participants drew detailed images of pituri and how pituri was harvested, dried and prepared for use, and wrote the words they used for pituri.Each participant demonstrated quid preparation, and demonstrated oral and postauricular quid placement.The participants sketched maps and identified locations where pituri was collected.In addition, the trigger list of nicotine's desired and adverse effects was compared to the participants' experiences of pituri use.The questions, discussion and responses were iterative, and further exploratory questions and responses arose throughout the knowledge-building dialogue.The responses were transcribed verbatim by AR, confirmed by the participant, AM and the interpreter, and clarified when necessary.
Data immersion consisted of the dialogue and reading the transcripts multiple times on multiple occasions.By using thematic analysis principles 20 , the text was organised into categories within the interview structure and inductively constructed as the information was studied.The categories were manually organised into themes.The commonality across the themes was constructed by AR and confirmed by AM.Manuscript drafts were translated back to the participants to confirm meanings and interpretations by LR (author three), who was not involved in the initial dialogue.

Ethics approval
Ethical clearance was obtained from the Human Research Ethics Committee of the University of Queensland (HREC Number 2015001429, 6 October 2015).

Results
The Learning Circle distinguished three main themes related to the primacy of pituri in Aboriginal life.These themes have been labelled to connect Aboriginal and Western epistemologies: • 'We all bin grind, grind'; pituri plants, preparation and use: ethnobotany • 'Crying for mingkulpa'; health and wellbeing: ethnopharmacology • 'Everyone very happy, we seen them plants'; family and community connectedness: ethnoculture • Quotes supportive of the themes are presented.The participants used the terms pituri and mingkulpa interchangeably; however, several other words and variations were used by the participants and are listed in Table 1.
'We all bin grind, grind'; pituri plants, preparation and use: ethnobotany Hard copy images of 15 laboratory Nicotiana spp.were presented; however, none was identified as being 'their mingkulpa'.The term mingkul-mingkul was used.(When a term is repeated, the value of the term is decreased, meaning 'a smaller object', 'not the true object', in this case referring to 'false mingkulpa, weak'.) The chemical analysis data from these laboratory plants were studied by the participants; however, as the participants hadn't recognised their mingkulpa within the images, they were dismissive of the plants and results.'That's that South Australian one; that's that Queensland one; that's that Western Australian one', noted Margaret (from the Northern Territory) as she scrolled through the images and read aloud the geographical information.When arriving at images labelled as being from the Northern Territory, she was slightly interested in the nicotine results, but as she didn't identify with the image, she moved on quickly.
When internet images of Nicotiana spp.were utilised, the respondents used the term mingkul-mingkul again.Only one image was considered by the group to be 'their mingkulpa'; this was the image of an Aboriginal man with a large Nicotiana spp.plant.The participants appeared to use the flowers to aid plant identification.Margaret commented several times 'that's not our one, that flower is wrong' in reference to the images of Nicotiana spp. with coloured flowers, and both Janet and Margaret were adamant that the internet Nicotiana spp.images weren't 'their mingkulpa', insisting on looking at 'more, more, more' in the hope of finding an exact image.Margaret was adamant that 'mingkulpa is not tobacco', and Maimie commented that 'the leaf is bigger [on the image of the commercial tobacco plant] than our mingkulpa'.Mingkulpa selection was similarly detailed by all participants.Janet described how the green leaves are plucked from the mingkulpa plants, allowing for continued growth; alternatively, some green stems with leaves are cut off, allowing continued growth from the main stem; however, she commented that if the plant is old, it will be 'pulled out, roots and all' to use.Maimie preferred to 'only take the leaves', with the stem remaining in situ; nonetheless, when 'no leaves are left … use the stem'.Margaret described and drew all three harvesting techniques that she used: pulling off the leaves, cutting off the stem or pulling out by the roots, and noted that in drought time tarka, the stems, are used.
The participants used similar principles for drying the harvest material.Janet placed the leaves directly on hot sand or a metal sheet, while Margaret placed a sheet on the ground and on which she placed the leaves and left them to dry in the sun.Collection and drying is done on a hot day and, at dusk, when the leaves are dry they are collected; Margaret commented, 'don't leave overnight or in plastic to dry'.The process of crushing the leaves is a group effort; Margaret described, 'we all bin grind, grind' as the leaves are crushed between rocks.Maimie explained that the broken and crushed leaves are then placed in a 'bag, pillow-case or wirra [wooden carrying dish]' as a storage place.Maimie recollected that 'in the early days' the leaves were 'placed in a ring of emu feathers' then 'tied up to carry'.Janet recalled carrying these emu feather bundles containing dried mingkulpa on her head.The participants confirmed that small quantities of the crushed mingkulpa are removed for the main supply for daily use.Contemporaneously, this personal supply is often carried in a Log Cabin or similar metal tin.
The participants described identical processes for the production of unu, the wood ash.Preferred trees are the kurku parka (Acacia aneura, a mulga tree), the white gum (Eucalyptus, a gum tree) or the bark from the ankerne (Corymbia opaca, a bloodwood tree).If a tree is used, small twigs with intact leaves are broken off and placed under the hot ashes of a campfire, the twig acting as a handle.When the leaves are dry, the twig is held over the fire while the leaves burn and their white ash is collected.Maimie described learning this process from watching her father do it.Janet noted that the taste of the ash verified if it was 'good ash'; if it had 'no taste' it was 'no good', and in addition if it 'doesn't blend in and gets up the nose' it was 'no good'.Generally a 'good quid' could last 2-4 hours, and ash was added again and again to 'get the last bit out'.Janet confirmed that 'campfire ash, never used'.Similar to the crushed mingkulpa, the ash is often carried in a metal tin.
Each participant demonstrated preparing a quid by spreading a small pinch of ash on their palm and adding mingkulpa (Fig3), moistening it with saliva and rubbing it between the hands.Margaret noted that mingkulpa can be mixed with human hair or rabbit fur to hold the quid together if needed.Each participant demonstrated the quid being placed just inside the lower lip but still visible, and confirmed and demonstrated that the quid was placed behind the ear when not in the mouth.As Maimie was positioning her ear quid, several previously stored quids fell out both from behind her ear and out of her hair, delighting her with the surprise finds.Maimie commented that 'I will hide it inside my mouth' and 'I carry a spare behind my ear'.Janet said 'we put mingkulpa on the lips, outside, some on the inside'.Janet said that the quid was changed when it became 'sour, worn out' or had 'no taste'.Janet and Maimie explained that they did not place the quid under a headband, armband or breast; however, Maimie recalled that in the 'early days, men' would place the quid under an armband.
All participants confirmed that when their mingkulpa supply was low, they would mix it with Log Cabin (and other commercial roll-your-own tobacco) or crushed cigarettes until further mingkulpa could be obtained.Margaret elaborated by saying 'buy cheapest smokes, break up, mix with the mingkulpa'; in addition, she commented that she was 'thinking of buying a cigar and breaking that up to try instead of Log Cabin'.When asked which was better, Janet commented that 'mingkulpa tastes better' and 'makes you feel better' and that Log Cabin 'makes you spit'.Margaret supported the assertion that mingkulpa was better, and in addition, commented that 'rollies are too sweet and make you spit, ppp,pp,pp'.Maimie indicated that Log Cabin was used on its own 'if it had to be' and was prepared by mixing with ash in the same manner as mingkulpa.Margaret also commented that 'people who like Log Cabin will mix the two, and that some people don't like mingkulpa on its own'.
'Crying for mingkulpa'; health and wellbeing: ethnopharmacology For Janet, mingkulpa use started around age 7 and has continued since; smoking was never taken up.As a 7-8 year old, Maimie had travelled from Warburton in Western Australia to Amata in South Australia and she 'joined in with mingkulpa' with the children there '… and that was it … I still use it now'.Maimie lamented that in her home location, the plants are scarce '… WA nothing'; however, her father and grandmother were both chewers and Maimie recollects as a child she and her family would walk from Warburton into South Australia 'looking for mingkulpa and then walk back again', around a 1400 km round trip to replenish 'good mingkulpa'.Margaret remembers that she tried cigarettes at 16-17 years old, but 'went on to mingkulpa'.
The participants reported that they 'like mingkulpa, it tastes good'.Asked to identify pleasurable mingkulpa effects from the trigger list of nicotine effects, the participants carefully all chose 'calmness', 'relaxation', 'improved concentration' and Margaret also added 'stress free' and that her concentration was 'a LOT better'.Using the trigger list, Janet and Maimie also considered that 'mingkulpa woke them up'; however, Margaret said 'it doesn't wake me up', and both Margaret and Maimie said it 'helps me sleep'.Janet and Margaret said it 'stops me feeling tired'; however, Maimie said it 'didn't stop me feeling tired'.The participants agreed that using mingkulpa 'stops feeling thirsty', and Janet mentioned that 'little tiny children would use mingkulpa to save themselves from dying of thirst'.Margaret also commented that it stopped her 'feeling hungry' and Janet noted that 'hungry ones travel with it and it keeps the mouth moist'.While Maimie and Janet said for them it 'didn't stop feeling sick', Margaret felt it did 'stop feeling sick'.
Maimie and Janet said that without mingkulpa they 'got nervous', which Janet elaborated as 'feels like when you're hungry, you need it'.Margaret expressed this feeling as 'like a crying for mingkulpa'; however, she said that she was able to 'block this out'.Maimie said 'without mingkulpa we talk too much, we growl and get grumpy, we get headaches'.Margaret explained that when you visit 'them old people, they been crying for mingkulpa'.And Janet said 'on dialysis, they are hungry for mingkulpa'.The participants highly value 'good' mingkulpa described as a 'proper cheeky bugger'; with a long contented sigh, Margaret spoke about Utju mingkulpa as 'Cloud 9 … I'm floating on a mingkulpa cloud'.
Margaret recalled that on one occasion she had a supply from Utju that caused her to 'nearly fall off the chair, I had to have water, water, water, more water, it was soooo strong'.All participants reported that they go to sleep with a fresh quid in their mouth.Janet noted that 'if I sleep without mingkulpa, I can't sleep … so I have it to sleep'.Margaret laughingly remarked that she will also 'wake up in the night and has a good chew'.).An admixture of Nicotiana spp.and wood ash supported the premise that the addition of wood ash would increase the pH of the pituri quid.A sample of N. gossei in distilled water had a pH of 5.5 and when mixed with an equal amount of the preferred wood ash, the pH of the quid was in the range 10.2-11.9(N.Moghbel, personal communication, January 2016).
When asked about swallowing the saliva produced when chewing or if it is spat out, Margaret commented that she 'doesn't swallow the spit, I just move the mingkulpa around'.Janet added that sometimes it is swallowed, but if it is, 'it burns'.Maimie confirmed this and said that 'lot of water' needs to be drunk if you 'swallow by accident'.Margaret supported these claims, saying she 'nearly choked when I swallowed once'.
Margaret insisted that the 'plant is pure, no chemicals', and is good for you; however, from the trigger list of adverse nicotine effects, the participants rapidly identified 'sick from mingkulpa' signs and symptoms, which Margaret said were experienced more 'in renal dialysis patients' and that 'normal people not so much'.Mingkulpa overdose and toxicity signs and symptoms as reported by participants include: • 'Really weak' Health uses of mingkulpa: The participants reported that wet mingkulpa was used on the skin in the treatment of ringworms, and in addition, Margaret said that the wet mingkulpa was used for 'bullant bite, yellow ant, itchy grub, caterpillar and spider bites' as well as 'scabies in hair' and 'skin sores'.Janet confirmed these uses, adding 'snake bite or scorpion … cut out the poison with a stone flake and put on mingkulpa'.Margaret recalled that as a child she had 'lots of insects bites and my mother she used lots of mingkulpa green leaves, grind, grind, always add the ash, wet leaf', and 'put this on my skin to stop the pain'.Janet added 'mingkulpa for the spear wounds, rubbing it one, then they'd travel long distances'.In contrast, Maimie commented that it 'was too precious to use for anything else', implying that mingkulpa was not willingly spared in her community for non-chewing purposes.
'Everyone very happy, we seen them plants'; family and community connectedness: ethnoculture Mingkulpa is a highly desired commodity, not just for its pharmacological effects.It holds a central role in the connectiveness of Aboriginal people to each other, their earthly place and their place in the cosmos; it secures for them individual and community happiness and contentment.Maimie stood up and passionately declared, and Janet and Margaret firmly endorsed, that: for Aṉangu, mingkulpa was, and is, and will be, a source of life Maimie commented that after a recent fire followed by rain, 'the mingkulpa came up everywhere, so everyone was there for it'.Janet enthusiastically noted that 'everyone very happy, we seen them plants'; for Aboriginal people to 'share [the plants] with people, make them happy'.Margaret explained that 'to show respect for the older people' and in observation of your responsibilities, 'people should take mingkulpa to the old people when they visit; it makes people happy, feel connected'.The gift of mingkulpa between family and friends is a sign of 'being loved'.'For senior people, mingkulpa is sacred, there is a sacredness to everything we eat', Margaret said.However, Maimie described that mingkulpa bags will be hidden from view because, as is the practice in Aboriginal culture, if it is requested by anyone, it must be shared, leaving little for the family responsibilities and personal use.
In response to being asked if people sell or buy pituri rather than simply gift it, Margaret commented 'selling it is not ideal, it is frowned upon, but you still buy it, because you [when you're in town] need it'.Maimie mentioned that in three bags she had bought in Alice Springs 'they were all different, I could tell, different colour, different tastes'.
When asked 'Who uses it?',the participants responded 'everyone uses it'.One participant noted that her paternal grandmother and father used mingkulpa and extensive travel was required and undertaken to obtain supplies.Another participant detailed that both grandmothers, mother, five aunties, both sisters and her daughter were chewers.The third participant counted both grandmothers, mother and sisters, both daughters and 'all five granddaughters use mingkulpa'.In terms of a 'rite of passage' or rules around mingkulpa, the participants' comments were similar.An older female chewer 'would offer you some when you were [a] strong girl'; in the geographical area of the three language groups, this was about the age of 7.While the participants generally started their own mingkulpa use at this age, one participant noted that 'all my grandchildren (all girls) started chewing at 5 years old'.Another participant too points out that one granddaughter was 'chewing from age 5 years', and that 'girl in town, she was 9 and chewing'.Margaret claimed that contemporaneously, children at 5 years old are being 'fed, or ask, or steal some of the mother's mingkulpa'; however, 'some parents are very strict and would never allow their children to try it'.
The participants could think of no restrictions or customary regulation on mingkulpa use; however, Margaret wryly said, 'don't take it through Customs'.Margaret explained this comment in relation to an overseas trip where Customs viewed 'that ash was like white powder, drugs' in the metal tins.
You think because you can't see it, it's not there: In recent discussions with a range of non-Aboriginal central Australian health providers, AR had been informed that 'we don't see women chewing like we used to' or 'we don't see women chewing'.AR put this statement to the participants.
All participants scoffed at this contention; 'shame', they said, or 'young ones, don't want to be seen.

Discussion
In this research, a Learning Circle methodology framed a knowledge-building dialogue between Aboriginal and non-Aboriginal participants that provided an opportunity for all to think in parallel dimensions.
Previous discussions with the larger consultative group had established that they identified no link between the brown shredded tobacco contained in commercial cigarettes and their green pituri plants.During the dialogue, images of laboratory grown plants and internet images of Nicotiana spp.were similarly rejected.It may have been that the laboratory plants grown under ideal temperature, light and water conditions appeared vastly different from those grown under desert conditions.
An apparent contradiction for the participants was the nonacceptance of 'their' mingkulpa as a tobacco plant alongside their mixing of commercial tobacco products with mingkulpa when in short supply.There would seem to be a realisation at some level that mingkulpa and commercial tobacco products have the same ability to provide desired effects, even if they aren't considered as being of similar botanical material.And in parallel contradiction, while the participants contended that mingkulpa was not harmful to health, they each expressed concern at the age that contemporary Aboriginal children commence using mingkulpa.Margaret says 'we are worried about very young children using mingkulpa, the parents should stop it'.
In itself, this is a thought-provoking outcome from the Learning Circle, given that the participants continued to challenge the notion that pituri equals tobacco.However, the concern around childhood use may have been influenced by the long lead-in time to the interviews wherein the botanical nature of pituri had been discussed and debated multiple times with the larger consultative group.
The participants' addition of wood ash to pituri was a clear demonstration of applied pharmacological principles.The preferred wood ashes all have demonstrated pH levels >11.5, able to modify the Nicotiana spp.pH and consequently the oral and skin pH to facilitate the absorption and release of nicotine from the plant cell 9 .Many world populations use nicotine orally; however, the adjunct post-auricular positioning of the quid demonstrates the sound pharmacokinetic principles practised by the Aboriginal women, with the site enabling the transdermal and continued absorption of nicotine through the very thin skin behind the ear 9 .These two methods of pituri use, however, provide for prolonged nicotine exposure, with additional exposure overnight as users sleep with a quid in situ.
Supportive evidence of the biphasic, tolerance and individual dose-response actions of nicotine was provided by the participants as they identified the effects of mingkulpa on themselves.Margaret's comments regarding 'Cloud 9 … I'm floating on a mingkulpa cloud' may be a high nicotine dose effect that can result in a narcotic-type experience 21 .Pharmacologically, nicotine overdose and toxicity have a range of signs and symptoms 9,21 .The participants acknowledged that there were undesirable effects such as sneezing, coughing and hiccoughing, and in addition, distinctly recognised being 'sick from mingkulpa' as evidenced by the outcomes that they quickly selected from the trigger list.Clearly, they had each experienced or witnessed symptoms of nicotine toxicity.
For the Aboriginal participants, articulating the central role that mingkulpa has in their lives, their communities, their connection to responsibilities, and their enjoyment of life was universal.The comment from Margaret regarding buying and selling pituri indicates that Aboriginal people will seek out pituri to meet those requirements.
The participants were adamant that mingkulpa use in their geographical areas was high and were dismissive of the assessment of non-Aboriginal health providers who don't see women chewing.The women used the term 'shame' as one reason to hide mingkulpa.For Aboriginal people, shame is a multifaceted, inherently cultural paradigm that Blagg 22 describes as being 'bound up with anxieties about a loss of social status, a feared mortification of a public self'.Being singled out (either favourably or unfavourably) creates anxiety and uncertainty and Aboriginal people will strive to avoid being 'shamed' 22 .
In terms of health outcomes, aside from the nicotine contained in Nicotiana spp., other compounds within the plant are of concern.The leaves contain a range of toxic chemicals, including carcinogenic nitrosamines that are potentially detrimental 6,9,23 .Furthermore, the ash and its addition to the quid produce changes to the ionic base with the possibility of other compounds being produced from the mixing process.Further investigation into the health outcomes of long-term exposure is required.

Strengths and limitations
The strength of this research included the engaged participation and direction from the consultative group and the highly interactive work of the Learning Circle.The Circle utilised what Riel 15 terms a 'knowledge building dialogue' between a 'meeting of equals' to establish a collective knowledge.The Circle provided all participants first-hand exposure to a research methodology, and the knowledgebased dialogue outcomes will be taken back to their respective communities, whether a remote outstation or an academic institution.The Learning Circle 15 technique was insightful, and powerful, and resulted in two-way Aboriginal and non-Aboriginal learning 24 and across-Aboriginal group learning as each language group listened to the others' stories.Riel 15 contends that this type of enabled, inclusive dialogue supports individuals to express first-hand experiences and is central to groups developing a collective responsibility for knowledge building.
The research focus and participation was limited to women in southern and western central Australia and so may not be transferable to other groups.Additionally, authentication of the findings and the reliance on interpreters to mediate knowledge between participants and non-Aboriginal researchers may have resulted in some loss of context.

Conclusions
The Learning Circle has recorded central Australian Aboriginal women's information on the location, harvesting, preparation and use of Nicotiana spp. as a chewing tobacco.The Circle established the Aboriginal women's ethnobotanical and ethnopharmacological knowledge around the preparation of pituri and the selection of ash to provide a self-administered, high concentration, nicotine delivery device.In addition, the central Australian Aboriginal women demonstrated sound ethnopharmacological knowledge of nicotine effects, overdose and toxicity.
In Australia, nicotine use as a health assessment variable is currently framed from within a Western paradigm related primarily to cigarette use; nicotine administered by other methods and formulations is not captured.Redesign of the Western health assessment tools is required to provide a wider and more inclusive approach to the assessment of nicotine use in the population.Furthermore, in central Australia, the health messages around commercial cigarettes and roll-your-own tobacco are framed from a Western perspective and are not considered by the consultative group or the participants as being applicable to their pituri.Contextualising health literacy information to populationspecific use of tobacco and nicotine would enhance the delivery of the health messages.
Inherently, Aboriginal people communicate extensively and intensely about the matters that they see as important to them and then determine the importance to their communities and advise how best to extend the discourse between Aboriginal and Western knowledge systems.The Learning Circle has facilitated the commencement of a 'knowledge community', the learning from which can now be disseminated into both Aboriginal and Western knowledge paradigms.

Future research
For the Aboriginal participants, the Aboriginal Action Research processes of the consultative group will drive the next endeavours.For the non-Aboriginal researcher, the integration of the Aboriginal knowledge into a Western paradigm will focus on the requirement to work with central Australian women to frame credible health literacy information about pituri as a smokeless tobacco.In addition, the wide spread and unacknowledged use of tobacco requires further investigation and will be conducted with and through the support of the Aboriginal consultative group.

Figure 1 :
Figure 1: Dispersal areas of the 22 species and four subspecies of Australian Nicotiana 8 .The map illustrates the heavier dispersal through the central area of Australia, with a range of species growing throughout that region.

Figure 2 :
Figure 2: Learning Circle Research Model adapted from Riel 15 .

Figure 3 :
Figure 3: Mingkulpa being mixed with ash in the palm of the hand prior to mastication.The background sketch identifies some preferred collection locations in southern central Australia; the metal tin is a preferred mingkulpa and ash-carrying container.(AR own photo with permission of Janet Inyika.)

Table 1 :
Central Australia Aboriginal names for Nicotiana spp.
They put it inside their cheek so you can't see it'.Maimie noted that if you wanted to hide the mingkulpa, you moved it to the 'inside of the lip or behind your ear'.Margaret said that it was a 'shame job to have it outside the mouth in front of white people you didn't know'.Margaret says that she 'like[s] to protect my mingkulpa inside my mouth.I don't want people to see the black thing on my mouth and wonder what it is.I practised putting it in my mouth.I don't want to spoil my good lips anyway'.The participants were adamant that pituri use in their communities was high, and that younger Aboriginal people will re-position their quid in the presence of non-Aboriginal people as 'they don't want to be shamed'; 'you think because you can't see it, it's not there', Margaret said.
This research was funded under the University of Queensland, Faculty of Health and Behavioural Sciences Research Collaboration Seeding Grant 2015 (Steadman, Ford & Bogossian, $11,470).AR is partially supported by a Queensland Health, Health and Medical Research Fellowship, the University of Queensland School of Nursing and Midwifery, Elizabeth A. Davies Scholarship, the Queensland Centaur Memorial Fund for Nurses Scholarship, and the Australian College of Nursing PhD Scholarship.