Acute toxicity of mixture of acetaminophen and ibuprofen to Green Neon Shrimp, Neocaridina denticulate

•The 96-h LC50 values obtained were 6.07 (5.33–7.84) mg/L and 6.60 (5.95–7.44) mg/L for acetaminophen (APAP) and ibuprofen (IBU), respectively in green neon shrimp.•The experimental results for mixtures containing unequal ratios of IBU and APAP indicated that mixtures with high APAP concentrations and low IBU concentrations exhibited markedly greater toxicity in green neon shrimp (LC50 = 4.78 mg/L) than APAP or IBU alone. However, mixtures with high IBU concentrations and low APAP concentrations exhibited lower toxicity in green neon shrimp (LC50 = 6.78 mg/L) than IBU or APAP alone.•We found different mixtures of acetaminophen and ibuprofen was associated with different toxic effects in green neon shrimp.

In recent years, numerous studies have indicated that various long-term use drugs, such as antibiotics or analgesics, not only cannot be completely decomposed via sewage treatment but also exhibit biological toxicity if they enter the environment; thus, the release of these drugs into the environment can damage ecological systems. This study sought to investigate the acute toxicity of two commonly utilized analgesics, ibuprofen (IBU) and acetaminophen (APAP), to aquatic organisms after these drugs have entered the water. To address this objective, the acute toxicity (median lethal concentration, LC50, for a 96-h exposure) of IBU alone, APAP alone, and mixtures containing different ratios of IBU and APAP in green neon shrimp (Neocaridina denticulata) were measured. The results of four tests revealed that the 96-h LC50 values for IBU and APAP alone were 6.07 mg/L and 6.60 mg/L, respectively. The 96-h LC50 for a 1:1 mixture of IBU and APAP was 6.23 mg/L, and the toxicity of this mixture did not significantly differ from the toxicity of either drug alone (p < 0.05). The experimental results for mixtures containing unequal ratios of IBU and APAP indicated that mixtures with high APAP concentrations and low IBU concentrations exhibited markedly greater toxicity in N. denticulata (LC50 = 4.78 mg/L) than APAP or IBU alone. However, mixtures with high IBU concentrations and low APAP concentrations exhibited lower toxicity in N. denticulata (LC50 = 6.78 mg/L) than IBU or APAP alone. This study demonstrated that different mixtures of IBU and APAP were associated with different toxic effects in green neon shrimp.