Chemical contaminant exposures assessed using silicone wristbands among fuel station attendants, taxi drivers and commercial motorcycle riders in Kampala, Uganda

Figures & data

Table 1. Demographic characteristics of participants.

	Number of participants
Characteristics	Commercial motorcycle rider (n = 5)	Taxi driver (n = 5)	Fuel station pump attendant (n = 4)	Total (n = 14)
Age in years: Median [IQR]	27 (24–28)	35 (31–42)	38.5 (28.5–49.5)	31.5 (25–42)
Sex: Male, n (%)	5 (100)	5 (100)	3 (75.0)	13 (92.9)
Education level, n (%)
Primary	2 (40.0)	3 (60.0)	2 (50.0)	7 (50.0)
Ordinary Secondary	3 (60.0)	1 (20.0)		4 (28.6)
Higher Secondary		1 (20.0)	2 (50.0)	3 (21.4)
Hours worked per week: Median [IQR]	84 (77–91)	96 (77–98)	72 (66–72)	77 (72–91)
Years in occupation: Median [IQR]	3 (3–3)	10 (5–10)	15 (6–22)	5.5 (3–10)

Note: IQR refers to Interquartile range.

Table 2. Confirmed PAHs levels by occupation.

PAHs, ng/g	Samples with detected levels		Occupation
	No.	Median (IQR)	Commercial Motorcycle rider	Taxi driver	Fuel station pump attendant	Kruskal Wallis test X^2 (p value)
Acenaphthylene	14	31.4 (27.3–42.6)	28.5 (27.3–31.7)	42.6 (31.0–48.3)	26.9 (18.4–42)	2.563, p = 0.278
Acenaphthene	2	53.6 (10.5–96.6)	53.6 (10.5–96.6)	–	–	–
Anthracene	6	41.3 (35.3–61.5)	36 (34.8–41.3)	–	81.3 (61.5–101)	3.429, p = 0.064
Fluorene	14	43.2 (34.2–61.5)	45.8 (40.6–52.2)	36.4 (34.2–54)	48.2 (17.4–94.3)	0.226, p = 0.892
Fluoranthene	14	180 (107–246)	126 (107–138)	255 (246–330)	152.5 (53.7–225)	0.280, p = 0.031
Naphthalene	14	46.4 (35.3–58.8)	46 (44.9–46.7)	31.9 (29.6–35.3)	63.4 (53.1–77.1)	6.786, p = 0.036
Phenanthrene	14	245 (204–305)	226 (204–264)	294 (206–305)	244 (133.1–346.5)	0.280, p = 0.869
Pyrene	13	174.5 (104–280)	104 (91.4–108)	235 (225–355)	236.5(102.8–320)	5.811, p = 0.055

Note: Average concentration (min-max).

Table 3. Common chemicals confirmed in all participants, by occupation.

15 Chemicals confirmed	Total	Average concentration (min-max)
	Median (IQR)	Commercial motorcycle rider	Taxi driver	Fuel station pump attendant	Kruskal Wallis for equality of medians X^2 (p values)
1,2,3-Trimethylbenzene	21.1 (11.8–26.2)	24.4 (18.3–34.2)	11.8 (11.3–20.6)	24.4 (16.0–46.5)	3.266, p = 0.1954
1,2,4-Trimethylbenzene	54.4 (28.5–71.6)	69.1 (44.7–107)	28.5 (24.2–56.1)	62.1 (37.8–141.3)	2.466, p = 0.2915
1,3,5 Trimethylbenzene	13.05 (7.77–16.5)	16.5 (11.3–24.2)	7.77 (6.45–13.6)	14.4 (9.3–30.2)	2.946, p = 0.2293
1,3-dimethylnaphthalene	37 (27.3–47.8)	30.3 (23.7––35.3)	40.6 (34.8–42.2)	70.4 (33–103)	2.443, p = 0.2948
1,6-dimethylnaphthalene	20.9 (14.7––29.4)	15.7 (12.9–17.2)	25.5 (19.7–26.2)	39.8 (18.4–57.9)	2.740, p = 0.2541
1-methylnaphthalene	21.1 (17.5–36.4)	17.6 (16.6–20.7)	21.5 (18.6–22)	32.7 (19.7–51.6)	1.826, p = 0.4014
2-methylnaphthalene	34.6 (29.8–54.2)	31.7 (29.8–35.8)	33.3 (28.7–42.8)	58.3 (39.6–83.5)	2.443, p = 0.2948
acenaphthylene	31.4 (27.3–42.6)	28.5 (27.3–31.7)	42.6 (31–48.3)	26.9 (18.4–42)	2.563, p = 0.2776
n-Decane	72.2 (39.6–93.4)	64.2 (41.5–80.2)	83.4 (51–98.2)	58.0 (22.1–89.9)	0.866, p = 0.6487
n-Dodecane	61.5 (45.6–134)	45.6 (38.5–45.6)	127 (77–140)	101.5 (61.5–210.5)	6.100, p =0.0474
n-Pentadecane	2775 (1580–5390)	1570 (1340–2000)	5230 (2140–8880)	5040 (3425–6770)	6.100, p =0.0474
n-Tetradecane	1355 (457–2400)	457 (396–639)	2450 (1550–3160)	1405 (932.5–2025)	5.126, p = 0.0771
naphthalene	46.4 (35.3–58.8)	46 (44.9–46.7)	31.9 (29.6–35.3)	63.4 (53.1–77.1)	6.786, p = 0.036
phenanthrene	245 (204–305)	226 (204–264)	294 (206–305)	244 (133.1–346.5)	0.280, p = 0.8694
Xylenes (m and p)	17.6 (11.3–31.7)	28 (12.1–51.7)	8.04 (2.64–16.7)	25.4 (15.4–84.4)	4.911, p = 0.0858

Note: Average concentration (min-max).

Data availability statement

The dataset used during the study is available from the corresponding author on reasonable request.