Artisanal and Small-scale Gold Mining in Syanyonja, Busia Gold District, South Eastern Uganda: Impacts on the Mining Population and the Environment

Aims: To determine the amount of mercury discharged into Namukombe stream, the major water body in Syanyonja village, Busia gold district and investigate the impacts of mercury-based artisanal and small-scale gold mining (ASGM) on the mining population and the environment. Study Design: Quantitation of mercury discharged with tailings was done by mass balance method. Field survey at the mining sites was done followed by administration of questionnaires to 50 stampeders in the village. study Methodology: Fieldwork was done in Syanyonja village to appreciate the level of environmental pollution due to mercurial ASGM in the area. Quantitation of mercury discharged with tailings was done by mass balance method. Field survey at the mining sites was done followed by administration of 50 questionnaires to stampeders of at least 18 years old and ASGM experience of not less one year. Results: About 8% of mercury mixed with auriferous materials is lost in tailings, accounting for an annual mercury release of about 1.757 kg into the environment. Socio-demographic results indicated that the majority of the mining population (64%) are male and ASGM have left human health and environmental footprints, which directly or indirectly affects the population. The most common health problems among miners are malaria (36%) and abdominal pain (20%). The standard of living of the miners are evidently low, and most mines are characterized by school dropouts, prostitutes and thieves. Mining sites have deplorably poor hygiene, with evident burning of amalgams to recover gold. Conclusion: ASGM have been accompanied by wanton mowing down of vegetation, land degradation as well as mercuric pollution of water, air, land and aquatic ecosystems. It is suggested that the Ugandan government should re-enforce committees to follow up on ASGM activities and train artisans on sustainable (non-mercury) alternative gold extraction methods that do not create new toxic exposures such as using borax, magnets and sluice boxes. Artisans should take up farming actively as an alternative.


INTRODUCTION
Uganda is a low-income landlocked African country with an averagely solid economic growth and demonstrated ambitions to attain a middleincome status by 2020 [1]. The country is at a juncture in its history of economic transformation preceding a decade of an apogee of Gross Domestic Product (GDP) growth that calamitously dwindled from 7% in 2009 to 3.9% in the fiscal year 2016/2017 [2,3]. Accordingly, the fiscal policy is badly advocating for capital investment to revitalize this GDP. The minerals sector which used to be informal and largely illegal is poised to contribute a pivotal part in this economic move as evidenced by its position of citation in the second National Development Plan for 2015 to 2020 [1].
The Ugandan government recently accorded artisanal mining greater cognizance through its prominent inclusion in a draft of the National Mining and Minerals Policy. This initiative is believed shall establish the basis for the upcoming mining laws and regulations and related strategies and actions by the government. In view of the foregoing, more robust evidence of the significance of artisanal mining and clarity on the opportunities and challenges presented by the sector are needed.
Busia have underground workings and surface mining of both alluvial and hard rock gold ores. The principal livelihood activities in this area include trade (as it is at the border with Kenya), gold mining and agriculture [9]. Up to 600 vulnerable people of Buteba, Sikuda and Busitema sub-counties in Busia subsist on ASGM. A demographic ratio of 4:1 (men to women) was reported, with individual annual earnings estimated at 17 million Uganda shillings [10].
Globally, the upsurge of ASGM and the growing awareness of the negative impacts of mercury use, both in terms of environmental and human health, has culminated in the drafting and ratification of the Minamata Convention which constrain signatories to phase out mercury use. As a contribution to decision making, this study evaluated the impacts of mercury-based ASGM in Uganda, taking evidence from Namukombe stream and its propinquity (Syanyonja village) as an example due to the intermittent ASGM in this area.

Brief Description of the Study Area
The study was conducted in Syanyonja village, Syanyonja Parish, Busitema subcounty, Samia Bugwe constituency, Busia gold district, South East of the Republic of Uganda. The choice of this area is explained by the high intensity of mercurial ASGM in it. Busia lies between 33°05' E 00°10' N and 34°01'E 00°35'N [6], covering an expanse of about 730.9 km² of land. It is flanked by Tororo district to the North, Kenya to the East, Lake Victoria to the South, Namayingo district to the Southwest and Bugiri district to the West [6].
Busia comprises of a mixture of auriferous hard rock (70%) and 30% alluvial soil which are part of the Cretaceous to Miocene intrusive alkaline carbonatite complexes of the Ugandan frontier with Kenya [4]. Namukombe stream, a tributary of River Malaba is one of the water bodies in Syanyonja village characterized by mercurybased ASGM activities [6] and was of interest in this study.

Apparatus Used
A calibrated Mettler PM200 analytical balance (Marshall Scientific, Hampton, USA), retort, single use disposable hand gloves, dust masks and eye googles.

Determination of Amount of Mercury Discharged with Slurry Tailings
Informal interviews with artisanal gold miners (stampeders) was conducted to assess the mercury losses during gold recovery. Mercury recovered after squeezing and panning the amalgams were estimated by mercury mass balance method described by preceding investigations [11,12].
The mass of mercury (quicksilver) entering the system (X g) was measured using an analytical balance before being introduced into the amalgamation process to concentrate gold with heavier particles in a pan. The mass of the solid mercury-gold amalgam formed (Y g) and the amount of pure gold recovered (Z g) were measured after amalgamation and panning respectively. The mass of mercury recovered after amalgamation (excess mercury), M g was determined from the mass of mercury recovered after squeezing the amalgam. The amalgam was burnt in open air on a retort to evaporate the mercury and then the solid was re-weighed and the mass noted.
The mass of mercury lost in the slurry tailings (discharged), D g was estimated from the difference in the masses of the mercury measured utilizing Equation 1.
The percentage of mercury discharged in slurry tailings was calculated from Equation 2.
The assumptions made were that no mercury was lost through evaporation during

Fig. 1. Administration of questionnaires in Syanyonja
amalgamation and losses due to adsorption onto pan walls are negligible. The procedure was repeated using different masses (2, 3, 4, 5 and 6 g) of mercury which are typical of the quantities of mercury used for amalgamation at different ASGM sites in Syanyonja village.

Collection of Field Data
Direct field observation was done in the mining sites in order to appreciate the rate of environmental destruction and the various phases involved in mercurial ASGM. The fieldwork in Syanyonja village was conducted between April 2019 and June 2019. Stamped (at least 18 years old with a seniority of at least 1 year and consenting) were selected. Because of the absence of an exhaustive list of stampeders working on the ASGM sites due to the intermittent nature of this activity, selection by simple random sampling was impossible. A quota sampling according to sex (1/3 of women, 2/3 of men) was performed considering the fact that approximately one-third of women work in ASGM sites [13]. To compensate for the selection bias associated with this type of sampling, the estimated size of the sample ( 25) was doubled to 50 respondents to cover potential non-respondents. In quantitative terms, the power of the target study was at least 75%, sufficient in the event where less than 50% of the stampeders are unaware of the impacts of mercury use in ASGM on miners and the environment [14]. Individual interviews (face to 4

Fig. 1. Administration of questionnaires in Syanyonja village
amalgamation and losses due to adsorption onto The procedure was repeated using different masses (2, 3, 4, 5 and 6 al of the quantities of mercury used for amalgamation at different Direct field observation was done in the mining sites in order to appreciate the rate of environmental destruction and the various phases involved in mercurial ASGM. The fieldwork in Syanyonja village was conducted between April 2019 and June 2019. Stampeders (at least 18 years old with a seniority of at least 1 year and consenting) were selected. Because of the absence of an exhaustive list of stampeders working on the ASGM sites due to the intermittent nature of this activity, selection by ampling was impossible. A quota sampling according to sex (1/3 of women, 2/3 of men) was performed considering the fact third of women work in . To compensate for the selection bias associated with this type of sampling, the estimated size of the sample (n = ) was doubled to 50 respondents to cover respondents. In quantitative terms, the power of the target study was at least 75%, sufficient in the event where less than 50% of the stampeders are unaware of the impacts of mercury use in ASGM on miners and the . Individual interviews (face to face) were conducted basing on an anonymous, standardized questionnaire ( Fig. 1 questionnaire captured socio characteristics, common illness in the area, number of family members engaged in ASGM, types and sources of proteinaceous food eat and the sources of water for domestic use (drinking) and for livestock.

Statistical Analysis of Results
All data collected in this study were entered into Microsoft Excel for Office 365 (version 16, Microsoft Corporation, USA). Statistical analyses (One-way ANOVA, averaging and other descriptive statistics) were done using Minitab statistical software (Version 17, Minitab Inc., USA). Statistical significance was set at

Mercury Lost in Slurry Tailings
The results of mercury discharged with tailings are given in Table 1.
About 8% of mercury used in amalgamation is discharged into the environment through slurry tailings during gold processing in Syanyonja and this poses a great threat to the environment. According to the interviewed mercury sellers around the mining sites, an average of 60 g of mercury is sold and used daily, implying that 4.8 g and 1,756.8 g of mercury are discharged into ; Article no.AJOGER.52582 ace) were conducted basing on an anonymous, Fig. 1). The questionnaire captured socio-demographic characteristics, common illness in the area, number of family members engaged in ASGM, types and sources of proteinaceous food eaten and the sources of water for domestic use

tatistical Analysis of Results
All data collected in this study were entered into Microsoft Excel for Office 365 (version 16, Microsoft Corporation, USA). Statistical analyses way ANOVA, averaging and other descriptive statistics) were done using Minitab on 17, Minitab Inc., USA). Statistical significance was set at P = .05.

SSION ercury Lost in Slurry Tailings
The results of mercury discharged with tailings About 8% of mercury used in amalgamation is discharged into the environment through slurry tailings during gold processing in Syanyonja and this poses a great threat to the environment. According to the interviewed mercury sellers an average of 60 g of mercury is sold and used daily, implying that 4.8 g and 1,756.8 g of mercury are discharged into the slurry tailings daily and annually respectively. A report [13] indicated that about 58% (n =118) of sampled gold stampeders in a study done in Mubende and Busia gold districts of Uganda used about 1-50 g of mercury per person weekly. This computationally translates into 2,800 g per stampeder per year. The results of this study is in complete agreement with the anecdotal finding of COWI [15] which observed that, although there were no recent estimates on the use of mercury for ASGM in Uganda, the mean mercury consumption per miner from Busia and Mubende gold-mining sites could give a mercury consumption rate of about 40.5 tonnes per year. This is further substantiated by an estimate which indicated that approximately 1,400 tons of mercury are used every year by ASGM miners globally [16]. In Rwamagasa ASGM area located in Geita district of Tanzania, about 27 kg of mercury was estimated to be released to the environment yearly, with about 12 kg of gold recovered from the process [17]. It is equally likely that the amount of mercury lost to the slurry tailings is re-emitted to the atmosphere on a relatively short time scale of one to several years as the tailings are accumulated in abovethe-ground piles and later reprocessed. It should therefore be over emphasized that the population living near to or downstream of Namukombe stream and the ASGM sites are at risk of mercury pollution [6].

Socio-demographic Characteristics and Exposure to Mercury
A total of 50 stampeders were contacted in this study. The characteristics of the participants are given in Table 2. The average age of the respondents was 26 years. The sample consisted of 64% men (n = 32) and 36% women (n = 18). There was no significant difference (P = .05) in the number of people who had stayed for 1 to 5 years and over 16 years in Syanyonja village ( Table 2). Most of the family members of the respondents (80%) were either directly or indirectly involved in mercury based ASGM. The gold mines were dominated by people between 20 years and above (70%) though children (stampeders below 18 years of age) constituted about 14% of the mining population (Table 2). Overall, the levels of child labour were higher in the ASGM sites and were more informal where participation were poverty rather than enterprise driven. Some of the children in these mines are orphans, are from child-led households or lack school fees and scholastic materials, corroborating preceding studies in other parts of Uganda [7,18]. This study also agreed well with previous reports that women realize fewer benefits from artisanal and small scale mining than men but bear the brunt of negative impacts [7,[19][20][21][22]].
In addition, the mines consisted of people of various ethnic origins namely: Bagishu, Basoga, the Iteso, Karamojong (Karimojong) and the Congolese. This is similar to a report [7] which cited that Acherer, an ASGM site in Karamoja region (Nakapirpirit district) hosts different ethnic groups: the Iteso, Western Ugandans and Rwandese during peak periods of ASGM. It is known that decentralization, economic turmoil, the ten-fold gold price increase within the period of 1996 to 2002 coupled by prospects of improved livelihoods from ASGM attracts unemployed people to engage in ASGM [7,20,23].
In terms of exposure, the findings indicated that most respondents (50%, n = 25) had spent 31 years or more using mercury, most of which (68%, n = 17) were women. In a similar crosssectional study in some sites of Mubende and Busia districts of Uganda, it was reported that 44% (n = 90) of the respondents had used mercury for ASGM for 1 to 4 years while the remaining percentage (56%, n = 114) had lived for 5 to 29 years handling ASGM mercury [13].    Pertaining health, it was noted that malaria (36%) abdominal pain (20%) tops the list of the in the last two (2) years (Table  ). This could be because pits left after harvesting auriferous rock materials holds stagnant water which act as breeding grounds for mosquitoes, the plasmodium vector which enhances the spread of malaria-P. falciparum and P. ). Abdominal pains are probably due to the manual nature of ASGM in Syanyonja which involves digging, crushing and panning of auriferous materials, usually involving bending for long hours in the scorching s artisans in Syanyonja employ rudimentary methods of gold extraction including panning typical of other ASGM sites in Uganda 21] (Fig. 2). Human health problems, diseases and neuropsychiatric disorders such as malaria, for long hours in the scorching sun [6]. Gold artisans in Syanyonja employ rudimentary methods of gold extraction including panning [6], typical of other ASGM sites in Uganda [18,20, ). Human health problems, diseases and neuropsychiatric disorders such as malaria, diseases (HIV/AIDS, gonorrhea, syphilis), musculoskeletal disorders and lower limbs and the back), sleep disruption (insomnia), headache, anorexia, tremor of the fingers, loss of fecundity and abnormal fatigue have been reported in 26].

Panning of alluvium along Namukombe stream : (a) by children (school dropouts). Notice the plastic tin used for storing recovered gold nuggets; (b) by a man. Notice the ditches rubs in the right )
It was noted that in Syanyonja gold mines, women are multitasked. They actively engage in ore processing and transportation, water collection, catering, prostitution, operate clinics amongst others. Unfortunately, this pivotal role played by women is not recognized in official ASGM policies [27] and in some cases they end up being victims of rape [18]. Also, ASGM is combined with domestic and reproductive work as well as small scale farming. Most women and girls are involved in low paying jobs, as most high paying opportunities are usually work prohibited by cultural norms for females to do. Therefore, women usually end up in panning, collecting water, transporting auriferous rock materials for crushing and burning of mercury in open air. Some operate eateries, sell airtime and consumables (such as waragi, cigarettes, cakes) around the mines. This is corroborant with preceding studies in Uganda [7,18,21,27].
Children taken to the mining sites may be exposed to atmospheric mercury vapour resulting from burning of amalgams in open air. Inhalation of mercury vapour results in high blood concentration of mercury implicated for many respiratory, neurologic, renal, immunologic, dermatologic and reproductive complications [28]. Human health impacts emanating from the utilization of mercury in ASGM have been reported in African countries of Benin [29], Burkina Faso [30], Ghana [31,32] and Mali [33]. This is evidenced by elevated levels of mercury in human blood, hair, urine and breast milk [26,34,35].
ASGM is largely a poverty-driven activity, used as a coping mechanism with thousands of families engaging in the mining practice [18,36]. This unfortunately exposes the miners to dermal contact with mercury in the dredged sediments as well as mercury-contaminated water [6]. Like reported for other parts of Busia (Tiira and Amonikakinei) [37], Karamoja region [7,18], Mubende and Buhweju [13,20,21], miners in Syanyonja village do not employ any form of personal protective equipment during mining activities. This could partly be due to lack of sufficient income to purchase them and lack of awareness on the dangers of mercury [21]. In addition, miners are also exposed to other heavy metals such as Copper, Lead and Chromium because these metals are naturally part of auriferous rocks as arseno-pyrite (FeAsS 2 ), Copper II Sulphide (CuS 2 ) and Iron (II) Chromium trioxide (FeO.Cr 2 O 3 ) [38,39]. These metals are released into the tailings during gold processing. Mbonimpa [9] also reported the presence of heavy metals in samples of rocks and sediments taken from around Namukombe stream and other areas between River Solo and River Malaba in Busia gold district. It is worth noting that most of the respondents as reported previously [13] have explicit fears regarding the health and ecological impacts of mercury usage in gold recovering, peculiarly on the risk of polluting food and water resources and losing fecundity.

Sources of Water Used for Drinking, Domestic Use and Animal Husbandry
In Syanyonja village, the weather pattern influences a household's choice of the main source of drinking and cooking water. Accordingly, more than half (55%) of the respondents reiterated that they rely on both borehole and Namukombe stream water for drinking and cooking purposes when compared to using borehole water only (Fig. 3). Many residents turn to the stream water when the dry season sets in and the boreholes are dry. Contamination of Namukombe stream, boreholes, springs and bottled water in Uganda are well documented [6,[40][41][42][43][44][45] and thus the results of this study agrees well with studies which indicated that ASGM communities in Uganda have contaminated ecosystems supporting their livelihoods [6,18,[46][47][48]. Water is an indispensable part of life on planet earth and the availability of sufficiently clean and safe water is an important aspect of a community [40].

Sources of Food
The various sources of food consumed in Syanyonja village are given in Table 3. The major foods consumed are beef, fish, chicken yams, beans, maize and millet flour. A preceding study indicated that fish and yams harvested from Namukombe stream are polluted with mercury [6]. Fish is widely consumed in many parts of Uganda [37,49,50] because it has high protein content, low saturated fat and also contains omega-3 fatty acids, calcium, phosphorus, iron, trace elements like copper and a fair proportion of the B vitamins known to support good health [6,49,51,52]. Besides the good health benefits of fish, there have been many reports on contamination of fish by carcinogenic chemicals in Uganda [6,49,53,54].
Since most of the foods consumed by the community are from within the village, there are high chances that the locals are consuming mercury-contaminated foods and these risks are expected to be high if most of the fish are consumed whole, especially by chi pregnant women [6]. Other foods such as beef, milk and yams are equally unsafe as they can also get contaminated through water, food and atmospheric deposition of mercury.

Impacts of ASGM on the environment of Syanyonja village
Field observations and responses gathered reveal that the major environmental problems of ASGM mining in Syanyonja village are deforestation, land degradation, soil erosion, dumping of tailings, air and water 2). Deforestation will leave degraded and fragmented habitats for wildlife [55]. More so, this shall increase the vulnerability of forest ecosystems to invasive plant and animal species. Exposure of top soil may initiate soil erosion  8 contaminated foods and these risks are expected to be high if most of the fish are consumed whole, especially by children or . Other foods such as beef, milk and yams are equally unsafe as they can also get contaminated through water, food and he environment observations and responses gathered reveal that the major environmental problems of ASGM mining in Syanyonja village are deforestation, land degradation, soil erosion, dumping of tailings, air and water pollution ( Fig.  ). Deforestation will leave degraded and . More so, this shall increase the vulnerability of forest ecosystems to invasive plant and animal species. Exposure of top soil may initiate soil erosion which when coupled with the open pits may lead to landslides [55].
Secondary impacts from erosion including sedimentation and siltation are evident in Namukombe stream. Siltation reduces light penetration into water bodies, causing reduced photosynthetic activity in aquatic organisms as well as increased biochemical oxygen demand, clogging of fish gills and thus death of aquatic organisms.
Wildcat pitting in many shallow pits and shafts across the mines were evident and these are excellent breeding grounds for mosquitoes other disease vectors. In addition, the numerous small shafts and pits dispersed across the mines are hazards for livestock and humans (particularly children), who may fall in the pits, causing loss of lives, income and time. These  Secondary impacts from erosion including sedimentation and siltation are evident in ream. Siltation reduces light penetration into water bodies, causing reduced photosynthetic activity in aquatic organisms as well as increased biochemical oxygen demand, clogging of fish gills and thus death of aquatic Wildcat pitting in many shallow pits and shafts across the mines were evident and these are breeding grounds for mosquitoes and other disease vectors. In addition, the numerous small shafts and pits dispersed across the mines estock and humans (particularly children), who may fall in the pits, causing loss of lives, income and time. These Percentage  10  46  41  3  44  20  32  4  32  64  4 observations have been reported in other ASGM sites of Uganda [7,18,48].

residents of Syanyonja village
It was noted that some parts of Namukombe stream is experiencing siltation due to the cumulative effects of water-intense gold panning. This has greatly increased the turbidity of water from this stream (Fig. 2). Turbidity greater than 5 Formazin Turbidity Unit (FTU) indicate high levels of bacteria, pathogens or particles that can shelter harmful organisms from disinfection [40].
Land is a key denominator in food production and economic development. Artisanal gold mining in Syanyonja is done on land that could otherwise be utilized for agriculture which supports food security. Reluctancy to backfill open pits exacerbate the situation. The interviewed stampeders are incrementally phasing out agriculture and other livelihood enterprises for mining as an economic activity that will salvage them from poverty. It is worth noting that ASGM cause environmental havocs in no small magnitudes [6,16,56] and therefore, as ASGM continue to be a valuable source of income to Ugandans, there is need to blend ASGM with environmental conservation [57].

CONCLUSION AND RECOMMENDA-TIONS
From this survey, the ecological and livelihood challenges associated with ASGM in Syanyonja definitely span beyond the anticipated benefits. Artisanal gold miners are typically poor, hardworking, illiterate with little or no formal education. Miners in Syanyonja are better acquainted with the health impacts of the mercury based ASGM than the accompanying environmental impacts. ASGM in Syanyonja have led to deforestation and pollution of land, air and water. Further research should examine the physicochemical and microbiological profile of the water sources utilized by the residents of Syanyonja village, the mercury levels in the blood, hair and urine of the community as well as the atmospheric flux of mercury in this area. Government should put prohibitive taxes on mercury imports and control its retailing to make mercury unaffordable and unavailable to the artisanal and small-scale gold miners in the move to phase out mercury use in ASGM.

CONSENT
As per international standard, miners' written consent has been collected and preserved by the author(s).

COMPETING INTERESTS
Authors have declared that no competing interests exist. The products used for this research are commonly and predominantly used products in our area of research and country. There is absolutely no conflict of interest between the authors and producers of the products because the authors do not intend to use these products as an avenue for any litigation but for the advancement of knowledge. Also, the research was not funded by any producing company rather it was funded by personal efforts of the authors.