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Activity:
Insecticide
(pyrethroid)
Structure:
Adverse
Effects:
Ataxia
Body
Weight Decrease
Bone
Brain
Cholesterol
CNS
Endocrine:
Breast
Endocrine: Suspected
Endocrine Disruptor
Endocrine:
Testes
Endocrine: Thyroid
Eye
Genotoxic
/ Clastogenic / Cytotoxic
Liver
Reproductive
Salivary
Glands
Tremors/Convulsions
Environmental
US:
Lambda-cyhalothrin and its isomer Gamma-cyhalothrin have
more than 380 food tolerances, including:
Alfalfa,
Egg, Garlic, Barley, Brassica, Cattle, Corn, Cotton, Goat,
Hog, Horse, Lettuce, Milk, Onion, Peanut, Poultry, Rice,Sheep,
Sorghum, Soybean, Sugarcane, Sunflower Seeds, Tomato, Wheat
There
is a separate food additive tolerance of 0.01 ppm for residues
of Lambda-cyhalothrin
in or on all food items (other
than those already covered by a higher tolerance as a result
of use on growing crops) in food-handling
establishments where food products are held, processed,
or prepared.
See
tolerances at: http://www.fluorideaction.org/pesticides/mrls.lambda-cyhalothrin.htm
|
Lambda-cyhalothrin
ranked number 21 for "Most Widely
used pesticides in the UK (by Area Treated)"
Rank
|
Formulation |
Method |
Area
treated (ha) |
Weight
applied (kg ai) |
21 |
Lambda-cyhalothrin |
Spray |
485,072 |
2,445 |
Ref:
April 29, 2000. UK Department for Environment, Food &
Rural Affairs in the online report, "Design of a Tax
or Charge Scheme for Pesticides. " Annex C3: Overview
of Pesticide Industry
http://www.fluorideaction.org/pesticides/pesticides.ranks.uk.2000.htm
|
Ataxia
(click on for all fluorinated pesticides)
A 12-month feeding
study in dogs fed dose (by capsule) levels of 0, 0.1, 0.5, 3.5
milligrams(mg)/kilogram (kg)/day with a no-observedeffect level
(NOEL) of 0.1 mg/kg/day. The lowest-observed-effect-level (LOEL)
for this study is established at 0.5 mg/kg/day based upon clinical
signs of neurotoxicity ataxia, muscle
tremors, convulsions.
Ref: Federal Register: March 27, 1995. Lambda-Cyhalothrin;
Pesticide Tolerances. Final Rule.
http://www.fluoridealert.org/pesticides/Lambda-Cyhal.FR.Mar.27.1995.htm
Body
Weight Decrease
(click
on for all fluorinated pesticides)
-- lambda-cyhalothrin.
13-Week feeding - rat. 00153028.
NOAEL: 2.5 mg/kg/day LOAEL: 12.5 mg/kg/day reduced
body weight gain and food consumption in
both sexes and food efficiency in females.
-- lambda-cyhalothrin. 21-Day dermal toxicity
- rat. 44333802. NOAEL: 10 mg/kg/day. LOAEL: 50 mg/kg/day.
clinical signs of toxicity, decreased body
weight and body weight gain.
-- lambda-cyhalothrin.
21-Day inhalation toxicity - rat. 41387702. NOAEL: 0.08
mg/kg/day. LOAEL: 0.90 mg/kg/day. clinical signs of neurotoxicity,
decreased body weight gains, increased
incidence of punctuate foci
in cornea, slight reductions in cholesterol in females,
slight changes in selected urinalysis parameters
Ref: Federal Register: September 27, 2002.
Lambda-cyhalothrin; Pesticide Tolerance. Final Rule.
http://www.fluoridealert.org/pesticides/Lambda.Cyhalot.FR.Sept27.02.htm
-- A carcinogenicity
study in mice fed dose levels of 0, 20, 100, or 500 ppm (0, 3,
15, or 75 mg/kg/day) in the diet for 2 years. A systemic NOEL
was established at 100 ppm and systemic LOEL at 500 ppm based
on decreased body weight gain in males
throughout the study at 500 ppm. The Agency has determined that
the chemical was not tested at a sufficiently high dose level
for carcinogenicity testing in female mice. In addition, due to
an equivocal finding for mammary tumors
in females (1/52, 0/52, 7/52, 6/52), the Agency classified the
chemical as a Group D carcinogen.
-- A developmental toxicity study in rats given gavage doses of
0, 5, 10, and 15 mg/kg/day with no developmental toxicity observed
under the conditions of the study. Developmental NOEL is greater
than 15 mg/ kg/day. Maternal NOEL and LOEL are established at
10 and 15 mg/kg/day, respectively. Reduced
body weight and food consumption were observed during the
dosing period.
-- A developmental toxicity study in rabbits given gavage doses
of 0, 3, 10, and 30 mg/kg/day with no developmental toxicity observed
under the conditions of the study. The maternal NOEL and LOEL
are established at 10 and 30 mg/kg/day, respectively (decreased
body weight gain was observed during the dosing period).
The developmental NOEL is 30 mg/kg/day (highest dose tested).
-- A three-generation reproduction study in rats fed diets containing
0, 10, 30, and 100 ppm with no developmental toxicity observed
at 100 ppm, highest dose tested. The maternal NOEL and LOEL for
the study are established at 30 (1.5 mg/kg/day) and 100 ppm (5
mg/ kg/day), respectively, based upon decreased
parental body weight gain. The reproductive NOEL and LOEL
are established at 30 (1.5 mg/kg/day) and 100 ppm (5 mg/kg/day),
respectively, based on decreased pup weight
gain during weaning.
Ref: Federal Register: March 27, 1995. Lambda-Cyhalothrin;
Pesticide Tolerances. Final Rule.
http://www.fluoridealert.org/pesticides/Lambda-Cyhal.FR.Mar.27.1995.htm
Bone
(click
on for all fluorinated pesticides)
Mutagenesis. 2005 May;20(3):235.
Induction of micronuclei by lambda-cyhalothrin
in Wistar rat bone marrow and gut epithelial cells.
No abstract available.
Authors: Celik A, Mazmanci B, Camlica Y, Askin A, Comelekoglu
U.
Note: FAN has requested a copy of this study from inter-library
loan.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15886259&query_hl=30
Abstract
(2005): In this study, a synthetic pyrethroid insecticide, lambda-cyhalothrin
(LCT), was administered to adult female albino rats (Wistar
rats) by gavage dose of 6.12, 3.06, 0.8 mg/kg b.w. repeated
for 13 days at 48 h intervals. The cytotoxic and genotoxic
effects of LCT were investigated in bone
marrow cells, using the structural chromosomal aberration
(SCA) and micronucleus (MN) test systems. Mitomycin C (MMC) was
also used as positive control (2 mg/kg b.w.). All
the doses of LCT increased the number of SCAs and the frequency
of micronucleated erythrocytes, with respect to the control group.
Only the highest dose of LCT significantly increased the MN frequency
compared with control (P<0.01). It was also observed that LCT
caused a significant decrease in the number of polychromatic erythrocytes
compared with controls (p<0.001). These
observations indicate the in vivo suspectibility of mammals to
the genetic toxicity and cytotoxicity potential of LCT.
Ref:
Evaluation of cytogenetic effects of lambda-cyhalothrin on Wistar
rat bone marrow by gavage administration; by Ayla Çelika
(a), Birgül Mazmanci, Yusuf Çamlica, Ülkü
Çömelekogšlu, and Ali As¸kin
Ecotoxicology and Environmental Safety - Volume 61, Issue 1 ,
May 2005, Pages 128-133
Abstract
(2003). In
this study, the genotoxic and cytotoxic potential of
lambda-cyhalothrin (LCT), a synthetic pyrethroid insecticide,
was investigated in Wistar rat bone-marrow
cells, using the structural chromosomal aberration (SCA)
and micronucleus (MN) test systems. LCT was administrated to adult
female albino rats as repeated i.p. doses of 6.12, 3.06, 0.8 mg/kg
BW for 13 days at 48 h intervals. Mitomycin C (MMC) was used as
a positive control (2 mg/kg BW). All the doses of LCT increased
the number of structural chromosomal aberrations and the frequency
of micronucleated erythrocytes, compared with the control group.
It was also observed that LCT caused a significant decrease in
the number of polychromatic erythrocytes. Our
results demonstrate that LCT has a clastogenic/genotoxic potential
as measured by the bone marrow SCA and MN tests in Wistar rats.
Ref:
Cytogenetic effects of lambda-cyhalothrin on Wistar rat bone marrow;
by Celik
A, Mazmanci B, Camlica Y, Askin A, Comelekoglu U. Mutat Res. 2003
Aug 5;539(1-2):91-7.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12948817
Brain
(click
on for all fluorinated pesticides)
Abstract (2004). The
peripheral effects of pyrethroids on Na(+) channels are well known
but the effects on CNS neurotransmission are less known. In the
present study, type I and II pyrethroids were found to affect
the release of acetylcholine (ACh) from hippocampus in freely
moving rats as measured by in vivo microdialysis. The basal release
of ACh from the hippocampus of untreated rats was 6.6 pmol/10
microl/10 min. Allethrin had an interesting dual effect on ACh
release, increasing ACh efflux (to about 300% of baseline) at
the lower dose of 20 mg/kg i.p. with a peak time of 60 min and
decreasing the efflux (to about 40% of baseline) at the higher
dose of 60 mg/kg i.p. up to 3 h after administration.
Cyhalothrin 20 and 60 mg/kg i.p. inhibited the release (to about
30% of baseline) dose-dependently, with a peak time of 50-60 min
after administration. Deltamethrin 20 mg/kg i.p. increased
the efflux (to about 250% of baseline) with a peak time of 30
min after administration and 60 mg/kg i.p. increased the efflux
(to about 450% of baseline) and remained at a steady level during
the rest of the 3 h experiment. Control vehicle injections had
no effect on the efflux of ACh in any of the experiments. This
is the first report, using in vivo microdialysis, that pyrethroids
modulate the ACh release in the hippocampus of rat brain.
Ref: The modulatory effect of pyrethroids
on acetylcholine release in the hippocampus of freely moving rats;
by Hossain MM, Suzuki T, Sato I, Takewaki T, Suzuki K, Kobayashi
H. Neurotoxicology. 2004 Sep;25(5):825-33.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15288513
Abstract (1990).
Ca2+ + Mg2+-ATPase from microsomal fractions of rat brain was
studied. The enzyme was activated by either Ca2+ or Mg2+ reaching
the peak at the Ca2+ concentration of 0.3 mM. Maximal activation
occurred at an ATP concentration of 5 mM with an apparent Km of
0.66 mM, a Vmax of 62.5 mumol inorganic phosphate/mg protein/hr,
and a pH between 8.1 and 8.5. The enzyme was found to be ouabain
insensitive but was inhibited by ruthenium red and lanthanum with
I50 values of 10-5 and 10-6 M, respectively. The enzyme was highly
sensitive to the actions of certain pyrethroid insecticides under
in vitro conditions. The cyano-containing
pyrethroids, karate and bathyroid, exerted a greater inhibitory
effect on the enzyme (Ki = 1.7 and 2 muM) than the non-cyano-containing
pyrethroids, permethrin and bioallethrin (Ki = 7 and 8.5 muM).
Ref: Properties of calcium, magnesium-ATPase
from rat brain and its inhibition by pyrethroids; by AL-RAJHI
DH. PESTIC BIOCHEM PHYSIOL; 37 (2). 1990. 116-120.
Abstract
(2003). Lambda-cyhalohrin is one of synthetic pyrethroids of family
of compounds with a-cyano-3-phenoxybenzyl moiety. The
aim of the work was to evaluate the influence of lambda-cyhalothrin
on memory processes, movement co-ordination and spontaneous movement
activity in mice exposed to transient oligemic brain hypoxia in
BCCA model. There were four groups of animals examined: I) sham-operated,
II) after BCCA, III) sham-operated, treated with beta-cyfluthrin,
and IV) after BCCA, treated with beta-cyfluthrin. Bilateral clamping
of carotid arteries (BCCA) is an experimental model of transient
ischemic attacks (TIAs), that occur in humans. 24 hours after
the surgery, the mice had a training in the passive avoidance
task. The next day the animals from group
III and IV were injected with 0,1 LD50 lambda-cyhalothrin intraperitoneally.
30 minutes after administration the animals were examined in the
passive avoidance task. Then, their movement co-ordination
on a rota- rod was examined. After that the mice were placed in
a Y maze to examine their spontaneous movement alterations and
later, their spontaneous movement activity was checked. Results
obtained were analysed with Anova and the post hoc tests. There
is a statistically significant difference (p<0,05) in spontaneous
movement activity within first 30 minutes of examination in group
IV versus I and after 60 minutes in group IV vs all the others
and in group II vs sham.
Conclusions: 1. Memory
retention is most impaired by lambdacyhalothrin in sham-operated
animals whereas BCCA-procedure protects their brains from pesticide’s
toxic action.2. Lambdacyhalothrin’s
effect on fresh spatial memory and spontaneous motor activity
is enhanced by BCCA.
Ref: LAMBDA-CYHALOTHRIN’S INFLUENCE
ON MEMORY PROCESSES, MOVEMENT CO-ORDINATION AND SPONTANEOUS MOVEMENT
ACTIVITY IN MICE EXPOSED TO TRANSIENT OLIGEMIC BRAIN HYPOXIA IN
BCCA MODEL; by Barbara Nieradko, Andrzej Borzecki. Toxicology
Letters, Volume 144, Supplement 1, 28 September 2003, Page s147.
[From Science Direct.]
Cholesterol
(click
on for all fluorinated pesticides)
Subchronic toxicity.
A 90-day feeding study in which rats were fed doses of 0, 50,
150, and 350 ppm with a NOEL of 50 ppm and a lowest observed effect
level (LOEL) of 150 ppm based on mild dose changes in hemoglobin,
cholesterol, and liver weight.
Ref: Federal Register: September 25, 1997
[Page 50337-50367]. Notice of Filing of Pesticide Petitions.
http://www.fluoridealert.org/pesticides/Lambda-cyhalothrin.FR.1997.htm
CNS
(click
on for all fluorinated pesticides)
-- Short term toxicity.
Target / critical effect: Organs Liver,
CNS. Lowest relevant oral NOAEL /
NOEL: 0.5 mg/kg bw/d, oral, 1 y dog.
Ref: European Commission. Review report
for the active substance lambda-cyhalothrin. Finalised in the
Standing Committee on Plant Health at its meeting on 19 October
2000 in view of the inclusion of lambda-cyhalothrin in Annex I
of Directive 91/414/EEC. 7572/VI/97-final. 25 January 2001.
http://europa.eu.int/comm/food/fs/ph_ps/pro/eva/existing/list1-24_en.pdf
--
lambda-cyhalothrin. 21-Day inhalation toxicity
- rat. 41387702. NOAEL: 0.08 mg/kg/day. LOAEL: 0.90 mg/kg/day.
clinical signs of neurotoxicity,
decreased body weight gains, increased incidence of punctuate
foci in cornea, slight reductions in cholesterol in females, slight
changes in selected urinalysis parameters
-- lambda-cyhalothrin.
1- Year
oral - dog. 40027902. NOAEL: 0.1 mg/kg/day. LOAEL: 0.5 mg/kg/day.
clinical signs of neurotoxicity.
--
lambda-cyhalothrin. Acute
neurotoxicity - rat. 44861510.
NOAEL: 10 mg/kg. LOAEL: 35 mg/kg. clinical
observations indicative of neurotoxicity and changes in
functional observational battery (FOB) parameters
Ref: Federal Register: September 27, 2002.
Lambda-cyhalothrin; Pesticide Tolerance. Final Rule.
http://www.fluoridealert.org/pesticides/Lambda.Cyhalot.FR.Sept27.02.htm
Abstract (2003).
Synthetic pyrethroids such as cyhalothrin are extensively used
in agriculture for the control of a broad range of ectoparasites
in farm animals. It has been suggested that type II pyrethroids
might induce anxiogenic-like effects in laboratory animals. The
present study was undertaken to investigate a possible anxiogenic-like
outcome of cyhalothrin in rats. Adult male
rats were orally dosed for 7 days with 1.0, 3.0, or 7.0 mg/kg/day
of cyhalothrin, present in a commercial formulation (Grenade Coopers
do Brazil S.A.). The neurobehavioral changes induced by
cyhalothrin as well as those produced on corticosterone serum
levels were measured 24 h after the last treatment. Picrotoxin
(1.0 mg/kg) was also acutely used as a positive control for anxiety.
Results showed that cyhalothrin:
(1) induced some signs and symptoms of intoxication that included
salivation, tremors, and liquid feces;
(2) reduced total locomotor activity in the open-field;
(3) reduced the percentage of time spent in open-field central
zones;
(4) increased immobility time in the open-field;
(5) reduced the percentage of time spent in plus-maze open arms
exploration;
(6) reduced the time spent in social interactions, and
(7) increased the levels of serum corticosterone.
The behavioral changes reported for cyhalothrin (3.0 mg/kg/day)
were similar of those induced by picrotoxin.
The no effect level dose obtained for cyhalothrin in this study
was 1.0 mg/kg/day. These results provide experimental evidence
that cyhalothrin induces anxiety-like symptoms, with this effect
being dose-related. Thus, anxiety must be included among
the several signs and symptoms of pesticide intoxication.
Ref:
Behavioral effects of type II pyrethroid cyhalothrin in rats;
by Righi DA, Palermo-Neto J. Toxicol Appl Pharmacol. 2003 Sep
1;191(2):167-76.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12946652
Endocrine:
Breast
(click
on for all fluorinated pesticides)
A carcinogenicity study
in mice fed dose levels of 0, 20, 100, or 500 ppm (0, 3, 15, or
75 mg/kg/day) in the diet for 2 years. A systemic NOEL was established
at 100 ppm and systemic LOEL at 500 ppm based on decreased body
weight gain in males throughout the study at 500 ppm. The Agency
has determined that the chemical was not tested at a sufficiently
high dose level for carcinogenicity testing in female mice. In
addition, due to an equivocal finding
for mammary tumors in females (1/52,
0/52, 7/52, 6/52), the Agency classified the chemical as a Group
D carcinogen.
Ref: Federal Register. March 27, 1995. Lambda-Cyhalothrin;
Pesticide Tolerances. Final Rule.
http://www.fluoridealert.org/pesticides/Lambda-Cyhal.FR.Mar.27.1995.htm
Endocrine:
Suspected Disruptor
(click on for all fluorinated
pesticides)
Suspected Endocrine Disruptor
Ref: PAN
Pesticides Database
Endocrine:
Testes (click
on for all fluorinated pesticides)
AIM: To assess the
effect of ICON (trade name of lambda-cyhalothrin) on sexual competence
and fertility of male rats.
METHODS: Male rats were gavaged daily for 7 consecutive days with
different doses of ICON (63 mg/kg and 100 mg/kg) or vehicle (distilled
water). Their sexual behaviour and fertility were evaluated at
different time points during treatment and post-treatment using
receptive females.
RESULTS: Treatment had no effect on fertility, but sexual
competence was seriously impaired: libido (assessed in
terms of pre-coital sexual behaviour, and numbers of mounting,
intromission and ejaculation), sexual arousability/motivation
(in terms of latencies for mounting, intromission and ejaculation),
sexual vigour (judged by frequencies of mounting and intromission
or copulatory efficiency). In addition,
ICON suppressed intromission ratio, indicating erectile dysfunction.
These effects on sexual function had a rapid onset and was reversible.
ICON-induced sexual dysfunction was mediated by multiple mechanisms,
mainly toxicity, stress, sedation and possibly via GABA and dopaminergic
systems.
CONCLUSION: Exposure to ICON may cause sexual
dysfunction in male rats.
Ref:
Effects of pyrethroid insecticide ICON (lambda cyhalothrin) on
reproductive competence of male rats; by Ratnasooriya
WD, Ratnayake SS, Jayatunga YN. Asian J Androl. 2002 Mar;4(1):35-41.
Full
free text available at http://www.asiaandro.com/1008-682X/4/35.htm
Endocrine:
Thyroid
(click
on for all fluorinated pesticides)
Limited data were available
regarding endocrine effects in animals following oral exposure
to pyrethroids. Serum levels of the thyroid
hormones T3 and T4 were significantly decreased in mice
administered fenvalerate at a dose level of 120 mg/kg/day for
15 days (Maiti and Kar 1998). Akhtar et al. (1996) reported similar
effects in rats administered bifenthrin or lambda-cyhalothrin
at daily oral dose levels of 0.5 mg/rat (approximately 0.75 mg/kg/day)
and 0.2 mg/rat (approximately 2 mg/kg/day), respectively, for
21 days. Lambda-cyhalothrin treated rats also exhibited a significantly
decreased serum T3/T4 ratio, relative to controls. In addition,
both bifenthrin and lambda-cyhalothrin treatment resulted in significantly
increased serum TSH levels, compared with control rats
(p 39)
Ref: September 2001. Draft
Toxicological Profile for Pyrethrins and Pyrethroids. US
Department of Health and Human Services. Public Health Service
Agency for Toxic Substances and Disease Registry.
Abstract (1996).
The effects of organochlorine, organophosphorus, and pyrethroid
insecticides on thyroid function were studied in rats. Young adult
male albino-rats were gavaged with 0.5 milligram (mg) per rat
heptachlor (76448), 0.60mg/rat benzene-hexachloride (58-89-9)
(BHC), 0.06mg/rat malathion (121-75-5), 0.2mg/rat O,S-dimethyl-phosphoramidothion
(10265-92-6) (Monitor), 0.5mg/rat bifenthrin
(82657-04-3) (Talstar), or 0.2mg/rat
lamdacyhalothrin (91465-08-6) (Karate)
daily for 21 days. They were then killed and weighed.
The serum was separated and analyzed for triiodothyronine (T3),
thyroxine (T4), and thyrotropin (TSH) using radioimmunoassays.
Except for Talstar, none of the insecticides affected body weight
gain. Talstar significantly decreased body weight gain. Heptachlor
and Monitor did not significantly affect serum T3, T4, and TSH
concentrations. Malathion, BHC, Karate, and Talstar significantly
decreased serum T3 and T4 concentrations and increased TSH concentrations.
Karate significantly decreased the T43 concentration.
None of the other insecticides altered the T4/T3 ratio.
The authors conclude that exposure to organochlorine,
organophosphorus, and pyrethroid insecticides for a relatively
short time can suppress thyroid secretory activity in young adult
rats. The decrease in body weight gain induced by Talstar
suggests that pyrethroid insecticides can inhibit growth rate.
Ref: Insecticide-Induced Changes in Secretory
Activity of the Thyroid Gland in Rats; by Akhtar N, Kayani SA,
Ahmad MM, Shahab M. Journal of Applied Toxicology, Vol. 16, No.
5, pages 397-400, 26 references, 1996.
Eye
(click
on for all fluorinated pesticides)
21-Day
inhalation toxicity - rat. 41387702. NOAEL: 0.08 mg/kg/day.
LOAEL: 0.90 mg/kg/day. clinical signs of neurotoxicity,
decreased body weight gains, increased incidence
of punctuate foci in cornea, slight reductions in
cholesterol in females, slight changes in selected urinalysis
parameters
Ref: Federal Register: September 27, 2002.
Lambda-cyhalothrin; Pesticide Tolerance. Final Rule.
http://www.fluoridealert.org/pesticides/Lambda.Cyhalot.FR.Sept27.02.htm
Genotoxic
/
Clastogenic / Cytotoxic
(click on for all fluorinated pesticides)
Abstract
(2005): In this study, a synthetic pyrethroid insecticide, lambda-cyhalothrin
(LCT), was administered to adult female albino rats (Wistar
rats) by gavage dose of 6.12, 3.06, 0.8 mg/kg b.w. repeated
for 13 days at 48 h intervals. The cytotoxic and genotoxic
effects of LCT were investigated in bone marrow cells, using the
structural chromosomal aberration (SCA) and micronucleus (MN)
test systems. Mitomycin C (MMC) was also used as positive control
(2 mg/kg b.w.). All the doses of LCT
increased the number of SCAs and the frequency of micronucleated
erythrocytes, with respect to the control group.
Only the highest dose of LCT significantly increased the
MN frequency compared with control (P<0.01). It was also observed
that LCT caused a significant decrease in the number of polychromatic
erythrocytes compared with controls (p<0.001). These observations
indicate the in vivo suspectibility of mammals to the genetic
toxicity and cytotoxicity potential of LCT.
Ref:
Evaluation of cytogenetic effects of lambda-cyhalothrin on Wistar
rat bone marrow by gavage administration; by Ayla Çelika
(a), Birgül Mazmanci, Yusuf Çamlica, Ülkü
Çömelekogšlu, and Ali As¸kin
Ecotoxicology and Environmental Safety - Volume 61, Issue 1 ,
May 2005, Pages 128-133
Abstract
(2003). In
this study, the genotoxic and cytotoxic potential of
lambda-cyhalothrin (LCT), a synthetic pyrethroid insecticide,
was investigated in Wistar rat bone-marrow cells, using the structural
chromosomal aberration (SCA) and micronucleus (MN) test systems.
LCT was administrated to adult female albino rats as repeated
i.p. doses of 6.12, 3.06, 0.8 mg/kg BW for 13 days at 48 h intervals.
Mitomycin C (MMC) was used as a positive control (2 mg/kg BW).
All the doses of LCT increased the number of structural chromosomal
aberrations and the frequency of micronucleated erythrocytes,
compared with the control group. It was also observed that LCT
caused a significant decrease in the number of polychromatic erythrocytes.
Our results demonstrate that LCT has a clastogenic/genotoxic
potential as measured by the bone marrow SCA and MN tests in Wistar
rats.
Ref:
Cytogenetic effects of lambda-cyhalothrin on Wistar rat bone marrow;
by Celik
A, Mazmanci B, Camlica Y, Askin A, Comelekoglu U. Mutat Res. 2003
Aug 5;539(1-2):91-7.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12948817
Abstract
(2003). Micronucleus
formation in fish erythrocytes, as an indicator of chromosomal
damage, has been increasingly used to detect the genotoxic potential
of environmental contaminants. Nucleolar organizer regions (NORs)
stained with colloidal silver techniques indicate sites of active
RNA transcription. The number and size of NORs in interphase nuclei
reflect cellular activities such as proliferation and differentiation
of cells. In this study, nuclear (micronucleus frequency) and
nucelolar (changes in quantitative characteristics of nucleoli)
biomarkers were used to evaluate the functional and structural
genotoxic effects of the pyrethroid insecticide lambda-cyhalothrin
on Garra rufa (Pisces: Cyprinidae). The frequency of micronuclei
was examined in blood smears obtained from fishes exposed to three
different concentrations (0.005, 0.01, 0.05 microg/l) for a period
of 36 h. Nucleolar parameters (the average number of nucleoli
per cell; the volume of a single nucleolus; and the percentage
of cells with heteromorphic paired nucleoli) were examined in
epithelial cells obtained from the edge of caudal fins at the
90th and 180th minutes of exposure. Results
of both tests demonstrated the genotoxic potential of pyrethroid
lambda-cyhalothrin on G. rufa. The
frequency of micronucleated erythrocytes was significantly increased
while the nucleolar parameters were repressed by lambda-cyhalothrin
treatment. Our results confirmed that the use of nucleolar
biomarkers on fish fin cells, in addition to micronucleus test,
could provide valuable information in aquatic genotoxicity studies.
Ref:
Evaluation of the genotoxic potential of lambda-cyhalothrin using
nuclear and nucleolar biomarkers on fish cells; by Cavas T, Ergene-Gozukara
S. Mutat Res. 2003 Jan 10;534(1-2):93-9.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12504758
Abstract
(1999). In
order to develop experimental models able to detect genotoxic
effects of pollutants in aquatic organisms, the genotoxicity of
the pyrethroid lambda-cyhalothrin was studied using the micronucleus
test in erythrocytes of Cheirodon interruptus interruptus. The
frequency of micronuclei was examined in blood smears obtained
from fishes exposed in vivo to three different concentrations
(0.05; 0. 01; 0.001 ug/l) of the compound and sacrificed at nine
sampling times (24, 48, 72, 96 h and 8, 12, 15, 19 and 23 days).
As a positive control fishes were exposed to 5 mg/l of cyclophosphamide.
Results obtained demonstrated the genotoxic
effects of the pyrethroid in the experimental model employed.
The variation in the micronuclei frequencies in the different
sampling times could be related to the blood cell kinetics and
the erythrocyte replacement. The results could be considered as
a validation of the MN test in fishes for the assessment of genotoxic
pollutants.
Ref:
Genotoxic evaluation of the pyrethroid lambda-cyhalothrin using
the micronucleus test in erythrocytes of the fish Cheirodon interruptus
interruptus; by Campana MA, Panzeri AM, Moreno VJ, Dulout FN.
Mutat Res. 1999 Jan 13;438(2):155-61.
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10036336&dopt=Abstract
Liver
(click
on for all fluorinated pesticides)
--
Short term toxicity. Target / critical effect: Organs: Liver,
CNS. Lowest relevant oral NOAEL / NOEL: 0.5 mg/kg bw/d, oral,
1 y dog.
Ref: European Commission. Review report
for the active substance lambda-cyhalothrin. Finalised in the
Standing Committee on Plant Health at its meeting on 19 October
2000 in view of the inclusion of lambda-cyhalothrin in Annex I
of Directive 91/414/EEC. 7572/VI/97-final. 25 January 2001.
http://europa.eu.int/comm/food/fs/ph_ps/pro/eva/existing/list1-24_en.pdf
Reproductive
/
Developmental (click on for all fluorinated pesticides)
Abstract (2003).
Icon is a water miscible type II synthetic pyrethroid insecticide
based on active ingredient lambda cyhalothrin
(10% w/w). It is used in Sri Lanka as an adulticidal indoor spray
against malaria vector mosquitoes. The goal of this study was
to assess the effects of Icon on pregnancy outcome of rats when
exposed during early pregnancy (days 1-7). Icon was gavaged daily
for 7 consecutive days in three different doses; 63, 83, or 125
mg/kg/day (active ingredient; lambda cyhalothrin; 6.3, 8.3, 12.5
mg/kg/day), respectively. Several parameters of reproduction and
pre- and post-natal development were monitored. The
results show that Icon is detrimental to pregnancy outcome (in
terms of quantal pregnancy, number of uterine implants, implantation
index and foetal deaths) but induced no detectable developmental
defects. The anti-reproductive effects of Icon were mainly due
to increased pre-implantation losses. Enhancement of post-implantation
losses played a subsidiary role. These effects resulted from multiple
mechanisms: maternal toxicity, stress, uterotropic activity and
embryo-foetotoxicity. Further progesterone had a protective effect
against Icon induced anti-reproductive actions.
Overall, the results suggest that exposure to Icon during early
gestation may result in a threat to pregnancy.
Ref:
Effects of Icon, a pyrethroid insecticide on early pregnancy of
rats; by Ratnasooriya
WD, Ratnayake SS, Jayatunga YN. Hum Exp Toxicol. 2003 Oct;22(10):523-33.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14655718
Abstract (2002).
AIM: To assess the effect of ICON (trade name of lambda-cyhalothrin)
on sexual competence and fertility of male rats.
METHODS: Male rats were gavaged daily for 7 consecutive days with
different doses of ICON (63 mg/kg and 100 mg/kg) or vehicle (distilled
water). Their sexual behaviour and fertility were evaluated at
different time points during treatment and post-treatment using
receptive females.
RESULTS: Treatment had no effect on fertility, but sexual
competence was seriously impaired: libido (assessed in
terms of pre-coital sexual behaviour, and numbers of mounting,
intromission and ejaculation), sexual arousability/motivation
(in terms of latencies for mounting, intromission and ejaculation),
sexual vigour (judged by frequencies of mounting and intromission
or copulatory efficiency). In addition,
ICON suppressed intromission ratio, indicating erectile dysfunction.
These effects on sexual function had a rapid onset and was reversible.
ICON-induced sexual dysfunction was mediated by multiple mechanisms,
mainly toxicity, stress, sedation and possibly via GABA and dopaminergic
systems.
CONCLUSION: Exposure to ICON may cause sexual
dysfunction in male rats.
Ref: Effects of pyrethroid insecticide ICON
(lambda cyhalothrin) on reproductive competence of male rats;
by Ratnasooriya WD, Ratnayake SS, Jayatunga YN. Asian J Androl.
2002 Mar;4(1):35-41. Full free text available at
http://www.asiaandro.com/1008-682X/4/35.htm
Salivary
Glands
(click
on for all fluorinated pesticides)
Gastrointestinal: Changes
in structure or function of salivary glands.
Ref: The Registry of Toxic Effects of Chemical
Substances. NIOSH.
http://www.cdc.gov/niosh/rtecs/gz12bc04.html#PCBPBS
Tremors/Convulsions
(click on for all fluorinated
pesticides)
A 12-month feeding
study in dogs fed dose (by capsule) levels of 0, 0.1, 0.5, 3.5
milligrams(mg)/kilogram (kg)/day with a no-observedeffect level
(NOEL) of 0.1 mg/kg/day. The lowest-observed-effect-level (LOEL)
for this study is established at 0.5 mg/kg/day based upon clinical
signs of neurotoxicity ataxia, muscle tremors,
convulsions.
Ref: Federal Register: March 27, 1995. Lambda-Cyhalothrin;
Pesticide Tolerances. Final Rule.
http://www.fluoridealert.org/pesticides/Lambda-Cyhal.FR.Mar.27.1995.htm
Environmental
(click
on for all fluorinated pesticides)
WHO/IPCS
evaluated lambda-cyhalothrin and classified it as "Moderately
Hazardous" (Class II), on the basis of acute oral toxicity
data (WHO 1999). The hazards and risks were summarized as
follows: harmful; irritating to eyes, skin and upper respiratory
system; ingestion could lead to neurological symptoms such
as tremors and convulsions; a hazard of ingested liquid
formulations is aspiration of the solvent into the lungs
(chemical pneumonitis); very toxic
to fish and honey bees.
... Lambda-cyhalothrin
is highly toxic to fish, aquatic arthropods and honey-bees
but WHO concluded that recommended use rates would not lead
to levels presenting environmental hazards.
Ref: 1999.
FAO Specifications and Evaluations for Plant Protection
products. Lambda-Cyhalothrin. Food and Agricultural
Organization of the United Nations.
Highly
toxic to fish and aquatic invertebrates.
"Cyhalothrin and lambda-cyhalothrin are very toxic
to fish in clean water under laboratory conditions. The
available data, summarized in Table 6, demonstrate a similar
high acute toxicity for both cold and warm water species
of fish... Cyhalothrin and lambda-cyhalothrin
have been shown to be toxic to honey-bees (Apis mellifera)
in laboratory tests (Table 10)."
Ref: ENVIRONMENTAL HEALTH CRITERIA
99: International Programme on Chemical Safety
http://www.inchem.org/documents/ehc/ehc/ehc99.htm#SubSectionNumber:6.2.2
Abstract: In Pakistan there is little data
on environmental contamination of rural water sources by
pesticides. This study evaluated pesticide contamination
of groundwater in four intensive cotton growing districts.
Water samples were collected from 37 rural open wells in
the areas of Bahwalnagar, Muzafargarh, D.G. Khan and Rajan
Pur districts of Punjab and analysed
for eight pesticides which are mostly used. Information
on types of pesticide used and distance to nearest pesticide
mixing area and application areas was obtained for each
site. From the eight pesticides analysed, six pesticides
were detected in the water samples. Only cypermethrin and
cabosulfan were not detected. The
percentage of detection of bifenthrin,
lambda-cyhalothrin, carbofuran,
endosulfan, methyl parathion and monocrotophos was, respectively
13.5%, 5.4%,
59.4%, 8%, 5.4% and 35.1% in July;
16.2%,
13.55%, 43.2%, 8%, N.D. (not
detected) and 24.3% in October.
Maximum contamination levels (MCLs) established by the U.S.
Environmental Protection Agency for drinking water were
not exceeded. The study has shown the need for monitoring
pesticide contamination in rural water resources, and the
development of drinking water quality standards for specific
pesticides in Pakistan. The conclusions and recommendations
will be disseminated to senior decision makers in central
and local governments, extension agents and farmers.
Ref: Pesticides in shallow groundwater
of Bahawalnagar, Muzafargarh, D.G. Khan and Rajan Pur districts
of Punjab, Pakistan; by Tariq MI, Afzal S, Hussain I. Environ
Int. 2004 Jun;30(4):471-9.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15031006&query_hl=11
Abstract:
The use of pyrethroid insecticides is increasing for agriculture,
commercial pest control, and residential consumer use. In
addition, there is a trend toward the use of newer and more
potent compounds. Little is known about the toxicity of
sediment-associated pyrethroid residues to aquatic organisms,
yet recent work has shown they commonly are found in aquatic
sediments in the heavily agricultural Central Valley of
California, USA. Minimal data exist on the sensitivity of
standard sediment toxicity testing species to pyrethroids,
despite two or more decades of agricultural use of these
compounds. Sediment concentrations
causing acute toxicity and growth impairment to the amphipod
Hyalella azteca were determined for six pyrethroids in three
sediments, ranging from 1.1 to 6.5% organic carbon (OC).
In order of decreasing toxicity of sediment-associated residues,
the compounds tested were bifenthrin
(average 10-d median lethal concentration [LC50] = 0.18
microg/g OC), lambda-cyhalothrin
(0.45 microg/g OC), deltamethrin (0.79 microg/g OC),
esfenvalerate (0.89 microg/g OC), cyfluthrin (1.08 microg/g
OC), and permethrin (4.87 microg/g OC). In a sediment containing
about 1% OC, most pyrethroids, except permethrin, would
be acutely toxic to H. azteca at concentrations of 2 to
10 ng/g dry weight, a concentration only slightly above
current analytical detection limits. Growth typically was
inhibited at concentrations below the LC50; animal biomass
on average was 38% below controls when exposed to pyrethroid
concentrations roughly one-third to one-half the LC50. Survival
data are consistent with current theory that exposure occurs
primarily via the interstitial water rather than the particulate
phase. A reanalysis of previously
reported field data using these toxicity data confirms that
the compounds are exceeding concentrations acutely toxic
to sensitive species in many agriculture-dominated water
bodies.
Ref: Use and toxicity of pyrethroid
pesticides in the Central Valley, California, USA; by Amweg
EL, Weston DP, Ureda NM. Environ Toxicol Chem. 2005 Apr;24(4):966-72.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15839572&query_hl=11
Abstract: The rainbow trout fish cell lines
RTG-2 and RTL-W1 were used to determine the cytotoxic effects
of the pesticides bifenthrin,
cypermethrin, cyhalothrin, lambda-cyhalothrin, quinalphos
and chlorpyrifos. Cytotoxicity was measured by EROD and
beta-Gal enzymatic activities, the neutral red (NR) uptake
assay, and the FRAME KB protein (KBP) assay. The beta-Gal
activity was unaffected by the pesticide exposure.
The EROD activity was induced by cyhalothrin and lambda-cyhalothrin
(RTG-2 and RTL-W1) and by bifenthrin (RTL-W1). Dose
dependent inhibition responses were observed for EROD activity
in cells exposed to quinalphos (RTL-W1) and chlorpyrifos
(RTG-2 and RTL-W1). RTL-W1 offered a better response for
EROD induction. The EC50 values on EROD endpoint were more
sensitive than NR and KBP. The acute fish toxicity of chlorpyrifos
and quinalphos depends highly on the species; the species
sensitivity distributions cover several orders of magnitude
and the values obtained for EROS were within the lowest
part of the reported ranges.
Ref: In vitro toxicity
of selected pesticides on RTG-2 and RTL-W1 fish cell lines;
by Babin MM, Tarazona JV. Environ Pollut. 2005 May;135(2):267-74.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15734586&query_hl=11
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