Table 10.

Human health risk assessment of pharmaceutical mixtures in one First Nation in the Boreal Shield ecozone in Ontario

Pharmaceutical	Max concentration (μg/L)	Health risk from mixture—females			% attribution
		ADI (μg/kg-d)	pGLV (μg/L)	BQ
Metformin	5.64	7.1	21.3	0.264789	55.59
Cotinine	0.0442	0.28	0.84	0.052619	11.05
Atenolol	0.245	2	6	0.040833	8.57
Diphenhydramine	0.044	0.4	1.2	0.036667	7.70
Carbamazepine	0.0272	0.34	1.02	0.026667	5.60
Codeine	0.0711	1.4	4.2	0.016929	3.55
Gemfibrozil	0.0154	0.41	1.23	0.012520	2.63
Diltiazem	0.0597	1.7	5.1	0.011706	2.46
Clarithromycin	0.0693	7.1	21.3	0.003254	0.68
Naproxen	0.0611	6.3	18.9	0.003233	0.68
Sulfamethoxazole	0.087	10	30	0.002900	0.61
Ibuprofen	0.052	11.4	34.2	0.001521	0.32
Metoprolol	0.0611	14	42	0.001455	0.31
Trimethoprim	0.0302	20	60	0.000503	0.11
Bezafibrate	0.0112	8.6	25.8	0.000434	0.09
Hydrochlorothiazide	0.0056	6	18	0.000311	0.07
Caffeine	0.336	6667	20,001	0.000017	0.004
Pentoxifylline	0.0127	24,000	72,000	0.0000002	0.00004
Risk quotient				0.476356

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