There is growing concern worldwide about the ASGM sector, and in particular the occupational health risks faced by ASGM workers. One strategy forward, as articulated in academic papers [12,13,14] as well as in the UN Minamata Convention (Annex C 1-c), is to take steps to formalize the sector. For example, a polling exercise that involved diverse ASGM stakeholders and experts from across Ghanaian institutions revealed that the promotion of conditions to help ASGM miners register, regularize, and develop their mining activities consistently scored amongst the most preferred option for improving the health, environmental, and socioeconomic problems faced by ASGM communities [13]. While there are widely held beliefs and anecdotes that unlicensed mining poses more occupational hazards than what may be found in a regulated or large-scale operation [11], to our knowledge there has been no empirical evidence generated in support of this notion. We believe the current study is the first to scientifically compare a group of licensed and un-licensed ASGM mine workers. In doing so, we are able to compare the groups in terms of their socio-demographics, ASGM work profiles, and injury rates.
In Ghana, like other countries, those who engage in illegal ASGM activities are often vilified in the media and by governments [15] leading towards a simple perception that these two groups are different. In the current study we found no striking socio-demographic differences (e.g., age, education level, living status, alcohol and cigarette consumption) between the miners currently working in a licensed and un-licensed site. Moreover, the fact that 98% of those miners who have worked at more than one site, have worked in both licensed and un-licensed sites at some point in time suggests that, at least in Ghana, there are not substantial or consistent differences with respect to the types (socioeconomic backgrounds, etc.) of individuals who may be found working in licensed vs. unlicensed mines. This also suggests that differences between licensed and unlicensed miners in terms of work-related safety (e.g., acute injuries) is most likely due to the differences in levels and types of hazards faced in the different types of mines, rather than any preexisting socioeconomic differences in the individuals employed (one exception from our work was related to work experience, and is discussed below). While there was a significant difference in terms of the number of females employed, this may likely not a true representation of the overall situation owing to the relatively small sample size. Here, only two women were sampled from the un-licensed ASGM sites and they reported zero injuries. The overall injury rate for females (11.9 injuries per 100 person years) is much greater than that of the men, and something that we previously discussed [9]. The role of females within the ASGM sector is important, discussed elsewhere by us and others [1, 16, 17], and warrants much more attention.
There is some difficulty in generalizing whether an ASGM miner exclusively operates in an illegal manner, and this represents an important limitation of the current study (and likely also other studies concerning ASGM). In the current study, 65 and 54% of miners working in a licensed and unlicensed site currently had worked only in that current site throughout their mining career. Of the remaining miners who have worked at two or more ASGM sites, 98% indicated to have worked in both licensed and unlicensed sites. As such, there is a tendency of many miners to move between licensed and unlicensed operations. In conversations we had with many study participants, they indicated being motivated mostly by financial gains and that they did not discriminate between the various mining sites based on their registration status, but rather on which of them had the ability to meet their financial demands. It should also be noted that ASGM miners in Ghana themselves are not licensed but rather the site in which they are operating.
Further comparisons of work characteristics between ASGM miners working in a licensed and unlicensed operation were revealing. Those who currently work in an un-licensed mine have been working longer in the ASGM sector. In terms of specific ASGM activities we queried (key ones being excavation, crushing and grinding, sifting and shanking, washing and sluicing, amalgamation, burning, and carrying loads) we found no difference between the groups. More than half of the respondents in each group indicated to being routinely involved in more than one activity. Although of potential interest, the proportion of un-licensed miners involved in amalgamation and burning was higher than the licensed miners. This could bode problems, in particular, for mercury exposure which others have shown to be largely due to burning activities [10]. Even though few miners are involved in burning mercury, the released chemical contaminates the entire worksite and broader community thus rendering everyone potentially exposed.
One of the key findings of the current study was the difference between the licensed and un-licensed miners with respect to their injury rates. The incidence proportion of injury was 17.3% for those working in a licensed mine versus 40.3% for those working in an un-licensed mine. Focusing strictly on the male miners, the injury rate among un-licensed miners (6.1 injuries per 100 person years) was significantly higher than licensed miners (4.2 injuries per 100 person years). In addition, among the miners with more than 5 years of work experience, the injury rates were more than 50% higher in the unlicensed group (5.2 injuries per 100 person years) than the licensed group (3.4 injuries per 100 person years). Comparing these values to other studies has proven challenging owing to the lack of information available. We are unaware of any studies comparing injury profiles (or other occupational and health measures) between licensed and unlicensed miners. Existing occupational health studies concerning ASGM are quite limited; they are largely descriptive, and vary greatly in methodology making it difficult to generalize and make comparisons. For example a previous study of small-scale miners in the Democratic Republic of the Congo [18] calculated an injury rate of 392 accidents per 100 person years though methodological differences (e.g., their sampling frame was one year and extended beyond ASGM) make it difficult to properly compare.
In addition to the injury rate we found that miners working in an un-licensed site tended to experience more injury episodes when compared to miners working in a licensed site though when stratified (1 injury event versus 2 or more) and normalized for person-years, we calculated no significant differences. The miners working in an un-licensed site also reported using less personal protective equipment during the time of the injury. A study from Ghana’s north found that the majority of ASGM miners do not use personal protective equipment including items such as hardhats, gloves, and steel toed boots [10]. Here we extend upon this study and report that the use of personal protective equipment may be less for those working in an un-licensed operation. Though, a limitation with our work is that we only queried about the use of personal protective equipment when an injury was self-reported, and so we do not have data on all the 404 miners that we engaged with. This would be an important area of future inquiry.
This study has several strengths. Foremost, to our knowledge it is the first epidemiological study to compare variables between miners who work in licensed and un-licensed ASGM sites. The sample size is relatively robust when compared to other ASGM studies, and the sampling strategy involving multiple sites was aimed at reducing bias. Nonetheless there are important limitations of our study that warrant mention. Recall bias is an inherent limitation in this type of study even though we utilized validated survey instruments and employed trained field staff, and also do not feel that those working in an un-licensed mine would recall past events differently than those working in a licensed mine. The sampling design was aimed at recruiting workers from both licensed and unlicensed sites. While it has been estimated that upwards of 85% of Ghana’s ASGM workers do not have licenses [19], we were unable to properly enumerate this in the study region though we have no reason to believe that the selected mines were atypical.