Effects of occupational heat exposure on female brick workers in West Bengal, India

Figures & data

Table 1 Results of questionnaire analysis (N=120)

Questions	Responses (%)
Awareness of heat stress symptoms	71.67
Discomfort during hottest days	99.17
Exhaustion during hottest days	94.17
Work productivity loss during hot seasons	89.17
Forced to work on hot days due to poverty	90.00
Productivity affects income on hotter days	98.33

N.B.: The percentage does not add up to 100% due to multiple responses.

Table 2 Physical characteristics of the female subjects

Parameters	Brick carriers (n=22), Mean±SD	Brick molders (n=18), Mean±SD	ANOVA significance
Age (years)	21.3±1.3 (18–23)	26.5±3.4 (19–30)	p<0.05
Height (cm)	146.4±3.25 (140.3–152.6)	145.1±3.33 (140.56–149.8)	NS
Weight (kg)	36.32±4.11 (26.7–40.5)	35.9±3.56 (24.8–38.37)	NS
Experience (years)	4.3±0.6 (0.5–5.0)	8.1±1.7 (2.5–6.2)	p<0.01

Range is shown in the parentheses.

Fig. 1 Thermal environmental variations (a, b) in the brick-manufacturing units.

Fig. 3 Variations of the working heart rates (beats/min) of the (a) brick carriers (n=22) and (b) the brick molders (n=18) in two seasons.

Fig. 2 Productivity of the (a) brick molders (n=88) and the (b) brick carriers (n=32) with respect to temperature changes in the working months.

Table 3 Cardiovascular parameters of the two groups of workers in two seasons

Groups	Parameters	Winter (WBGTout index: 16.1°C to 19.4°C), Mean±SD	Summer (WBGTout index: 26.9°C to 30.7°C), Mean±SD	ANOVA significance
Brick carriers	SRHR (beats)	1552.25±12.32	1552.97±16.88	NS
(n=22)	NCC (beats)	1257±122.69	1259.64±136.96	NS
	RCC (%)	81.40±3.16	83.58±5.08	NS
	HRp (beats/min)	123.55±5.11	124.93±10.82	NS
Brick molders	SRHR (beats)	798.21±100.80	995.85±16.83	p<0.0001
(n=18)	NCC (beats)	923.36±135.61	1091.64±116.53	p<0.001
	RCC (%)	75.77±5.99	80.54±3.03	NS
	HRp (beats/min)	115.25±9.04	121.85±5.13	p<0.05

Table 4 Observed variations of speed (km/hour) in two seasons while walking with or without a load of bricks

	Summer (WBGTout: 26.9–30.7°C)		Winter (WBGTout: 26.9–30.7°C)
Groups	With load	Without load	With load	Without load
Brick carriers (n=22)	2.0±0.21	3.8±0.15	3.3±0.1	4.8±0.3
Brick molders (n=18)	2.9±0.1	4.1±0.7	3.8±0.07	5.4±0.13

Table 5 Statistical significance between the observed walking speeds (km/hour) of the two groups of workers in two seasons

Groups	Parameters	F value	ANOVA significance
Brick carriers (n=22)	With load (summer) vs. with load (winter)	19.43	p<0.01
	Without load (summer) vs. without load (winter)	6.47	p<0.05
	With load (summer) vs. without load (summer)	10.04	p<0.01
	With load (winter) vs. without load (winter)	7.33	p<0.01
Brick molders (n=18)	With load (summer) vs. with load (winter)	5.12	p<0.05
	Without load (summer) vs. without load (winter)	7.25	p<0.01
	With load (summer) vs. without load (summer)	10.31	p<0.01
	With load (winter) vs. without load (winter)	5.01	p<0.05