Acute Toxicity of Double-Walled Carbon Nanotubes to Three Aquatic Organisms

Table 1

Growth inhibition (EC₅₀s and 95% confidence intervals) for Pseudokirchneriella subcapitata following 72 h exposure to pristine and oxidised DWCNTs at different ionic strengths and humic acid (HA) concentrations. EC₅₀s with common alphabetical superscript do not differ significantly ().

Exposure	Physicochemical characteristics	EC50 (mg/L)	Confidence limits (mg/L)
Pristine	0.00335 (control reconstituted water) M Na	17.95^a	9.8–26.72
	0.00585 M Na	29.47^a	22.95–37.65
	0.00835 M Na	30.89^a	18.06–40.4
	0.0139 M Na	52.31^b	33.96–76.1
Oxidised	0.00335 (control reconstituted water) M Na	10.93^a	6.71–15.59
	0.00585 M Na	27.22^a	19.56–38.9
	0.00835 M Na	16.11^a	11.59–22.42
	0.0139 M Na	49.31^b	27.24–58.89
Pristine	0.00449 M Ca	23.26^a	17.04–28.00
	0.0226 M Ca	25.57^a	16.07–34.93
	0.0339 M Ca	31.52^a	21.56–50.92
Oxidised	0.00449 M Ca	22.86^a	15.59–42.42
	0.0226 M Ca	22.91^a	12.95–40.89
	0.03395 M Ca	24.61^a	13.37–34.44
Pristine	0 (control reconstituted water) M Na	17.95^b	9.80–26.72
	0.9 mg/L HA	22.75^a	14.39–31.70
	1.81 mg/L HA	26.56^a	10.95–34.61
	3.64 mg/L HA	31.65^a	10.87–42.19
Oxidised	0 (control reconstituted water) M Na	10.93^a	6.71–15.59
	0.9 mg/L HA	13.59^a	8.71–21.19
	1.81 mg/L HA	18.01^a	16.71–24.93
	3.64 mg/L HA	20.56^a	6.58–34.15