Table 2. The organ index of mice after 270 days consecutive exposure.

Organ	Organ index (mg g–1)
	Control	Zn ions	ZnO-NPs	ZnO-MPs
Female mice
Heart	3.85 ± 0.80	3.76 ± 0.65	4.01 ± 0.75	4.56 ± 0.27
Liver	38.92 ± 3.34	35.86 ± 5.61	39.08 ± 7.55	49.86 ± 4.46*
Spleen	3.25 ± 0.88	2.34 ± 0.53*	3.52 ± 1.40	3.55 ± 0.60
Stomach	9.23 ± 1.16	7.35 ± 1.17*	8.66 ± 1.28	10.93 ± 1.73
Kidneys	10.88 ± 1.67	10.32 ± 1.65	11.20 ± 2.40	13.10 ± 1.15
Lungs	6.39 ± 1.22	5.70 ± 1.13	5.62 ± 1.04	7.06 ± 0.46
Brain	13.5 ± 3.8	11.62 ± 2.59	11.94 ± 2.62	14.32 ± 1.72
Large intestine	11.66 ± 2.59	8.76 ± 2.03*	11.01 ± 1.77	16.37 ± 2.55*
Small intestine	30.86 ± 8.84	21.56 ± 5.81*	28.15 ± 6.30	38.97 ± 10.19
Male mice
Heart	4.68 ± 0.40	5.65 ± 0.98*	5.27 ± 0.62*	4.87 ± 0.66
Liver	46.36 ± 5.32	49.40 ± 4.75	47.32 ± 4.43	51.44 ± 5.86
Spleen	3.03 ± 1.23	4.03 ± 1.41	3.14 ± 1.00	2.52 ± 0.78
Stomach	7.94 ± 1.17	8.17 ± 1.17	8.05 ± 1.52	10.09 ± 5.31
Kidneys	14.74 ± 1.45	17.11 ± 2.47*	15.62 ± 2.60	15.94 ± 0.68
Lungs	5.55 ± 1.54	6.81 ± 2.27	5.55 ± 0.64	5.81 ± 0.43
Brain	9.05 ± 0.91	10.24 ± 0.75	9.70 ± 1.93	10.84 ± 0.92
Large intestine	11.37 ± 0.65	10.42 ± 1.88	10.25 ± 1.31*	10.65 ± 2.68
Small intestine	31.32 ± 4.04	31.50 ± 9.42	27.70 ± 4.43	29.74 ± 4.03