Loom Owning Households (%)
3.6 Parameters
3.6.1 Assessment of Illumination (Lux
)The illumination measurement procedure was followed as per the studies conducted by Dianat, 2013 and Küller et al., 2006 and illumination level on the handloom units was measured using standardized methods (Chengalur et al., 2004; Padmini and Venmathi, 2012) in accordance with task, working plane, point of operation using the Auto Digital Lux meter [Model No. 1010A, Make M/s Sigma, 2011]. Data was recorded in the sheet to observe the lux value which has been measured during the whole day for four times at an interval of four hours at four locations (i.e. three points on the front side of the handloom and one point on the back side; Fig. 3.5) in the prevailing working illumination conditions on each handloom (Fig. 3.6) every month for 12 months. During measurement of illumination value the subjects were asked to weave on the handloom as per with their daily prevailing illumination conditions and light sources.
Fig. 3.5 Sketch diagram of handloom depicts the locations for measuring the illumination values at four points.
Fig. 3.6 Original loom image signifies the positions L1, L2, L3 and L4 for measuring the illumination values.
3.6.2 Estimation of Noise (dBA)
The noise level (A-weighted sound level) on the handloom units was measured within worker’s hearing zone (Bureau of Indian Standards, 2005a); Chengalur et al., 2004;
OSHA, 2013; Bridger, 2002; Singh et al., 2009 as prescribed by International Electrotechnical Corporation) using sound level meter [Model KM 929, Make M/s Kusam Meco, 2014] in worker’s working position operating the handloom. The noise level (in dBA) was measured at two different locations, one near the right ear of the weaver and another at the centre of the shed every month for the whole year on each handloom. For each point, two readings i.e. Maximum and Minimum were taken. There are four types of weighting the sound which are known as A, B, C and D scales in the sound meter out of which dBA scale (or weighting function) is widely used in industries (Helander, 1995). Hence all the values were measured in ‘dBA’. Noise level was measured on the handlooms which were in operation.
3.6.3 Physiological Measurements
Heart Rate. The heart rate of the weaver was measured by counting the pulse of the dominant hand of the weaver at supine rest before they started working on the handloom as per their daily routine.
Measurement of discomfort rating using Borg CR 10 scale. Discomfort rating of the weavers was evaluated by using the Borg CR10 (Category Ratio) scale. The exact site of discomfort is specified using the body map (Corlett and Bishop, 1976), which is ORIGINAL LOOM IMAGE SHOWING ‘L4’ POSITION ORIGINAL LOOM IMAGE SHOWING L1, L2, L3 POSITIONS
divided into different segments (Fig 3.7). Depending on the region of discomfort, pain is mapped in that segment. Borg CR10 scale (Borg, 1982a, 1998,) is used to rate the level of discomfort in terms of pain from Grade 0 (No pain) – Grade 10 (Excruciating / Extremely Strong).
Borg CR10 scales:
0 Nothing at all 0.5 Extremely Week 1VeryWeek
2 Week 3 Moderate / Mild 5 Strong
6 Moderate Strong 7 Very Strong 10 Excruciating / Extremely Strong
Fig. 3.7 Body map for identification of areas of discomfort for rating on Borg’s scale.
3.6.4 NASA Task Load Index for Cognitive Psychological Assessment
NASA Task Load Index (TLX) is the most widely accepted subjective multidimensional tool for assessing subjective workload on the operator(s) working with various human-machine systems (Hart and Staveland, 1988). This tool is used to rate perceived cognitive workload on 6 different subscales such as (1) mental demand, (2) physical demand, (3) temporal demand, (4) performance, (5) effort and (6) frustration, and thus determine an overall workload score, based on the weightedaverage of the ratings using these subscales. The reliability of the NASA TLX scale is very good (r = 0.83; Singh et al., 2005). Based on a weighted average of ratings the NASA TLX scale provides an overall workload score (Singh et al., 2005; Singh et al., 2010 a).
3.6.5 Questionnaires for the assessment of impact of illumination and noise
Two Questionnaires were designed after reviewing and consulting several available questionnaires, journals, publications, research papers, literature and established parameters compiled by various standard organizations. The 7-Point Likert Scale is a psychometric response scale primarily used in questionnaires to obtain participant’s preferences or degree of agreement with a statement or set of statements. This is a non‐comparative scaling technique and measures only a single trait. Respondents are asked to indicate their level of agreement with a given statement on an ordinal scale.
Borg’s CR10 Scale Rating is also used in the questionnaire to ascertain the perceived exertion of various discomfort factors. The 7-point Likert scales are advantageous because they are simple to construct, likely to produce a highly reliable scale and easy to read and complete for participants. Using such a 7-point Likert scale (where 1 depicts very low, 2 low, 3 moderate, 4 medium, 5 moderate high, 6 high and finally 7 represents very high), weavers rated their reactions to the prevailing illumination and noise conditions on the workplace.
Questionnaire on the impact of illumination.
The questionnaire to evaluate illumination contained 60 questions framed considering demographic, physiological and psychological aspects. Questions related to demographic parameters have been adopted from the publications of earlier researchers (Wargocki et al., 2012 and Toftum et al., 2012). Questions on physiological aspects prepared with the help of various publications, literature and research papers (Sanjog et al., 2013; Howarth, 2005; Cameron, 1996; Borg, 1982; Agarwal and Yadav, 2013; Borg, 1998). Questions related to psychological measures were constructed after various publications and standards (Parsons, 2005; Howarth, 2005; Wargocki et al., 2012;
Pejtersen et al., 2006 and Simone et al., 2012).
Questionnaire on the impact of noise.
A total of 43 questions were designed considering all the aspects as in case of questionnaire for light, viz. the demographic, physiological and psychological components. Questions related to demographic parameters had been constructed in light of previous works (Eleftheriou, 2002; Cheung, 2004; Öhrström et al., 1979 and Zytoon, 2012). Questions on physiological aspects have been comprehended after Öhrström et al., 1979; Agarwal and Yadav, 2013 and Borg, 1998. Psychological components were fabricated after consulting existing reports (Eleftheriou, 2002; Zytoon, 2013; Öhrström et al., 1979; Hart, 2006; Agarwal and Yadav, 2013; Borg, 1998 and Toftum et al., 2012).