Table 12.

Human health risk assessment of pharmaceutical mixtures in the second of the two First Nations located in the Mixedwood Plains ecozone in Ontario (Ontario 2)

Pharmaceutical	Max concentration (μg/L)	Health risk from mixture—females			% attribution
		ADI (μg/kg-d)	pGLV (μg/L)	BQ
Metformin	1.36	7.1	21.3	0.063850	33.53
Cotinine	0.0507	0.28	0.84	0.060357	31.69
Carbamazepine	0.0423	0.34	1.02	0.041471	21.78
Codeine	0.0339	1.4	4.2	0.008071	4.24
Atenolol	0.04	2	6	0.006667	3.50
Hydrochlorothiazide	0.0449	6	18	0.002494	1.31
Naproxen	0.0433	6.3	18.9	0.002291	1.20
Warfarin	0.00067	0.16	0.48	0.001396	0.73
Sulfamethoxazole	0.0391	10	30	0.001303	0.69
Gemfibrozil	0.0013	0.41	1.23	0.001057	0.56
Clarithromycin	0.0094	7.1	21.3	0.000441	0.23
Ranitidine	0.013	11	33	0.000394	0.21
Metoprolol	0.0124	14	42	0.000295	0.16
Bezafibrate	0.0029	8.6	25.8	0.000112	0.06
Acetaminophen	0.014	50	150	0.000093	0.05
Trimethoprim	0.0046	20	60	0.000077	0.04
Clofibric acid	0.0012	10	30	0.000040	0.021
Caffeine	0.115	6667	20,001	0.000006	0.003
Risk quotient				0.190416

ADI, acceptable daily intake; pGLV, a provisional guideline value; BQ, benchmark quotient