Environmental risk assessment of the insecticide Cartap in bioassays with three invertebrates

The ecotoxicological impact of the insecticide cartap, extracted from the marine polychaete Lumbrinereis   spp., was evaluated on three representative organisms of the animal community. The microcrustaceans Moina macrocopa   (Sars) (freshwater environment) and Porcellio laevis   Latreille (terrestrial environment), and also the parasitoid microhymenopterans Muscidifurax raptorrellus   Kogan & Legner (aerial environment) were used as side effect organisms on different models of acute bioassays at 24 and 48 h of exposure to determine the toxicological impact of cartap. The LD 50 (mean lethal dose) of P. laevis and the LC 50 (mean lethal concentration) of M. macrocopa and M. raptorrellus , allowed the calculation of the risk quotients (RQs) for the environmental risk assessment (ERA) of this product in the ecosystem. The analysis of ERA and LT 50 (mean lethal time) indicated a moderate impact for cartap on the environment

Ecotoxicological effects of three heavy metals on the root growth of four vascular plants

Environmental risk assessment (ERA) of terrestrial environments polluted by heavy metals in Peru requires standardized biological organisms, the use of which is simple, practical, sensitive and repeatable, such as seeds of higher plants used in eco-toxicological bioassays. The aim of this research was to evaluate the phytotoxic effects of Cr6+, Hg2+ and Pb2+ as potassium dichromate (K2Cr207), mercury chloride (Cl2Hg) and lead acetate ((CH3C00)2Pb), respectively, on growing roots of four species of higher terrestrial plants: onions (Allium cepa   L., Liliaceae), red beets (Beta vulgaris   L., Chenopodiaceae), rice (Oriza sativa   L., Poaceae) and radishes (Raphanus sativus L., Brassicaceae) at 192 h (8 days) exposure. Bioassays of static sub-lethal toxicity for each metal and for each species of plant were performed, using a randomized complete block design: six concentrations and eight replicates with 240 seeds for each bioassay. The sequence in ascending order for mean inhibition concentration (IC50 in mg L-1) on root growth at 192 h exposure in the majority of cases was: Hg2+ > Cr6+> Pb2+. The perspectives of use for evaluation of soils contaminated by heavy metals in Peru are analyzed

Employing the freshwater snail Physa venustula Gould as an ecotoxicological tool for environmental risk assessments by pesticides

A standardized ecotoxicological evaluation of soil pesticides such as lindane, chlorpyrifos and metamidofos was realized at Federico Villarreal University, Lima, Peru, employing the freshwater snail Physa venustula   as a tool for environmental risk assessment. The values determined for mean lethal concentration (LC 50 ) for the lethal effect of the pesticides evaluated were at 24, 48 and 96 h of exposure respectively: lindane 811.89, 715.30 and 415 m g L -1 ; chlorpyrifos 379.13, 154 and 66.01 m g L -1 and metamidofos 1 791, 391.33 and 194 m g L -1 . Sublethal effects were observed with chlorpyrifos and metamidofos. The CE 50 values determined for disadherence at 24, 48 and 96 h respectively were chlorpyrifos 197.14, 89.14 and 36.23 m g L -1 , and metamidofos 600.81, 361.69 and 150.75 m g L -1 . The values for cephalic detachment at 24, 48 and 96 h of exposure respectively were chlorpyrifos 323.69, 109.02 and 60.01m g L -1 , and metamidofos 738.4, 314.4 and 155.93 m g L -1 . Of the three evaluated pesticides, the decreasing order of ecotoxicity for the lethal effects, at 24 h of exposure was chlorpyrifos > lindane > metamidofos; and at 48 h and 96 h was chlorpyrifos> metamidofos > lindane. For sub-lethal effects the decreasing order of ecotoxicity at 24, 48 and 96 h was chlorpyrifos > metamidofos. This protocol of ecotoxicological assays using P. venustula is proposed as a tool for the evaluation of environmental risks of soil pesticides

Evaluación del riesgo ambiental del insecticida metamidofos en bioensayos con cuatro organismos acuáticos no destinatarios

The aim of this research was to evaluate the ecotoxicological effect of methamidophos using two formulations of different toxicological class [Monofos®, class Ia (extremely dangerous) and Tamaron®, class Ib (highly dangerous)] on four non-target aquatic organisms: bloodworm Chironomus calligraphus (Goeldi, 1905) (Diptera: Chironomidae), black sea urchin Tetrapygus niger Molina, 1782(Echinodermata: Arbaciidae), neon tetra Paracheirodon innesi (Rabout, 1940) (Osteichthyes: Characidae); and rainbow trout Oncorhynchus mykiss (Walbaum, 1792) (Osteichthyes: Salmonidae). Both methamidophos formulations evidenced a high risk effect on the aquatic environment, finding effects on larvae of C. calligraphus (Class Ia, LC50 at 48 h = 1.32 mg a.i. L-1 and Class Ib, LC50 at 48 h = 4.5 mg a.i. L-1), on fertilization of T. niger (Class Ia, IC50 at 1 h = 1423 mg a.i. L-1 and Class Ib, IC50 at 1 h = 608 mg a.i. L-1), on P. innesi (Class Ia, LC50 at 96 h = 20.56 mg a.i. L-1 and Class Ib, LC50 at 96 h = 10.13 mg a.i. L-1) and O. mykiss (Class Ib, LC50 at 96 h = 19.12 mg a.i. L-1). The sequence of sensibility to methamidophos in both formulations was: C. calligraphus > O. mykiss ≈ P. innesi > T. niger.In addition, two sublethal effects were evaluated on P. innesi, immobilization and strange swimming, and finally an increment of opercular movement in O. mykiss. Risk quotients (RQ) indicated in all cases a high risk of methamidophos towards the aquatic environments.El objetivo de este trabajo fue evaluar el efecto ecotoxicológico del metamidofos, en dos formulaciones de diferente categoría toxicológica [Monofos®, categoría Ia (extremadamente peligroso) y Tamaron®, categoría Ib (altamente peligroso)] sobre cuatro organismos acuáticos no destinatarios: la lombriz roja Chironomus calligraphus (Goeldi, 1905) (Diptera:Chironomidae), el erizo negro Tetrapygus niger Molina, 1782(Echinodermata: Arbaciidae), el neón tetra Paracheirodon innesi (Rabout, 1940) (Osteichthyes: Characidae) y la trucha Oncorhynchus mykiss (Walbaum, 1792) (Osteichthyes: Salmonidae). Ambas formulaciones del metamidofos provocaron un alto riesgo sobre el ambiente acuático, al encontrarse efectos sobre las larvas de C. calligraphus (Clase Ia, CL50 a 48 h = 1,32 mg i.a. L-1 y Clase Ib, CL50 a 48 h = 4,5 mg i.a. L-1), sobre la fertilización de T. niger (Class Ia, CI50 a 1 h = 1423 mg i.a. L-1 y Clase Ib, CI50 a 1 h = 608 mg i.a. L-1),en P. innesi (Clase Ia, CL50 a 96 h = 20,56 mg i.a. L-1 y Clase Ib, CL50 a 96 h = 10,13 mg i.a. L-1) y en O. mykiss (Clase Ib, CL50 a 96 h = 19,12 mg i.a. L-1). La secuencia de sensibilidad al metamidofos en ambas formulaciones fue: C. calligraphus > O. mykiss ≈ P. innesi > T. niger.En adición, se evaluaron dos efectos subletales en P. innesi, inmovilización y nado extraño, y finalmente, incremento de movimiento opercular en O. mykiss. Los cuocientes de riesgo (CR) indicaron en todos los casos un alto riesgo del metamidofos en el ambiente acuático