CHAPTER 2: LITERATURE REVIEW
3.2 RESEARCH DESIGN
This study was a cross sectional observational study conducted on SA rural forestry workers in winter in KZN (2005) and in autumn in Mpumalanga (2006).
63 3.3 SAMPLE SELECTION
3.3.1 Region selection
Within SA, the regions of KZN and Mpumalanga were selected solely on the basis that the majority of the commercial forestry plantations are situated within these areas as illustrated by Figure 7 (South African Forestry 2006). Neither climate nor altitude was taken into consideration.
Figure 7: Location of commercial forests in South Africa (permission for use granted by the South African Forestry Magazine)
64 3.3.2 District selection
The districts selected within these regions were decided on the basis of convenience.44
3.3.3 Study site selection
Richmond (KZN) and Nelspruit (Mpumalanga) were included because harvesting was occurring in these areas during the time of each study and there were contractors in these areas who employed sufficient labourers to meet the sample demands and who had the reputation of being both fair and reputable. The forestry industry was concerned that those contractors who did not meet the minimum wage and safety requirements would interfere with the execution of the study by being totally uncooperative and the industry felt that this study would be difficult enough to execute without additional resistance.
The districts selected therefore represented the “best case scenario”.
As each contractor was harvesting a large area of the forest, the study sites were again selected on the basis of convenience. To be considered for inclusion, the area needed to be within an hour’s drive from where the research team was based, needed to be physically accessible without the use of 4x4 vehicles and needed to have enough forestry workers harvesting within the area to meet the sample demands.
44The research sites and research samples were selected by Francois Oberholtzer (Institute of Commercial Forestry Research ), Pierre van Daele (Mondi) and Andre Brink (South African Pulp & Paper Industry).
65 3.3.4 Selection of study population
The participants were again selected on the basis of convenience. The Nelson Mandela Medical School statistician (Esterhuizen 2005) could not calculate a required sample size with any precision as there were no previous relevant studies using USG from which this could be extrapolated. As a result it was recommended “as large a sample size as possible”. In each area the sample size was determined by the available funding45
In Richmond the forestry workers harvested in teams
as well as the number and proficiency of the members in the research team.
The forestry industry had stipulated that the sample was to be comprised of chainsaw operators, chainsaw operator assistants, rough liners, debarkers and stackers. To ensure a representative sample of each job category, the method of selection differed slightly between the two areas.
46 comprising both males and females. The number of research assistants (RA’s),47
45The study was funded by ICFR.
46The members of each team were consistent. Each team comprised of 1 chainsaw operator, 1 chainsaw operator assistant and 8 rough liners.
47The term RA refers to all members of the team other than the supervisors regardless of whether they were dieticians, translators or CHW.
as well as the quantity of data to be collected, limited the sample number to 2 teams (n=20) per day. The first two teams who arrived at the site each morning who had not been included in the study on the previous days, were chosen (Table 6). Eight of the 10 teams harvesting in the area participated.
The total sample number was 79. This consisted of 8 chainsaw operators, 8 chainsaw operator assistants and 63 rough liners.
66 Table 6
In Nelspruit, rather than working in small teams, the workers harvested in large groups according to their job category. As there were a greater number of RA’s in the Nelspruit research team, the sample number was increased from 20 to 25 per day. On Day 1 all the chainsaw operators and chainsaw operator assistants were included as well as 5 debarkers (Table 7). On Day 2 the first 25 female debarkers who arrived at the site, and who had not taken part the previous day, were included. On Day 3 a combination of debarkers and stackers were sampled in the same manner and on Day 4 stackers only were included.
Female debarkers were selected to meet the forestry industry’s stipulation that a representative sample of females was included. In this area females were only employed as debarkers. A hundred and three workers out of the total work force of 250 were sampled. These consisted of 11 chainsaw operators, 9 chainsaw operator assistants, 41 debarkers and 42 stackers. Although the sample size should have been 100, some workers were distressed at being left out of the study and were included to avoid unrest.
: Sample selection in Richmond
Job category Day 1
(n)
Day 2
(n)
Day 3
(n)
Day 4
(n)
Total
(n)
Chainsaw operators 2 2 2 2 8
Chainsaw operator assistants 2 2 2 2 8
Rough liners 16 15* 16 16 63
Total 20 19 20 20 79
* There should have been 16 rough liners but one was absent due to illness.
67 Table 7
Job category
: Sample selection in Nelspruit
Day 1
(n)
Day 2
(n)
Day 3
(n)
Day 4
(n)
Total
(n)
Chainsaw operators 11 11
Chainsaw operator assistants 9 9
Debarkers 5 25 11 41
Stackers 17 25 42
Total 25 25 28 25 103
There were no exclusion criteria for subject selection on either study site.
As this was an observational study, there was no control group.