4 research outputs found
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 Â
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 categorÃa
toxicológica [Monofos®, categorÃa Ia (extremadamente
peligroso) y Tamaron®, categorÃa 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