toxicological profile for malathion - Agency for Toxic Substances and ...

a
Key to
figure
96
Species
(Strain)
Exposure/
Duration/
Frequency
(Specific Route)
Neurological
Mouse 80 wk
(B6C3F1)
ad libitum
(F)
97 Mouse 18 mo
(B6C3F1)
Reproductive
ad libitum
(F)
98 Mouse 80 wk
(B6C3F1)
Cancer
ad libitum
(F)
99 Rat 2 yr
(Fischer- 344)
ad libitum
(F)
100 Mouse
(B6C3F1)
18 mo
ad libitum
(F)
System
Table 3-2 Levels of Significant Exposure to Malathion - Oral
NOAEL
(mg/kg/day)
20.8 F
Less Serious
LOAEL
Serious
(mg/kg/day) (mg/kg/day)
(continued)
2980 F (generalized body tremors from
week 71 to 79)
143 M (24% and 44% inhibition of 1476 M (90% inhibition of plasma and
plasma and RBC cholinesterase
activity, respectively)
RBC cholinesterase activity)
1490 F (cystic endometrial hyperplasia)
868 F (CEL: increased incidence of
combined hepatocellular
adenoma and carcinoma)
1476 M (CEL: increased incidence of
combined hepatocellular
carcinomas and adenomas)
Reference
Chemical Form
NCI 1978
Slauter 1994
NCI 1978
Daly 1996a
Slauter 1994
a The number corresponds to entries in Figure 3-2
b Only this dose level, the lowest effect level, is plotted in Figure 3-2.
c Used to derive an intermediate-duration oral minimal risk level (MRL) of 0.02 mg/kg/day; The MRL was derived by dividing the NOAEL by an uncertainty factor of 10 to account for
human variability.
d Used to derive a chronic-duration oral minimal risk level (MRL) of 0.02 mg/kg/day; The MRL was derived by dividing the NOAEL by an uncertainty factor of 100 (10 for animal to
human extrapolation; 10 for human variability).
e Differences in levels of health effects and cancer between males and females are not indicated in Figure 3-2. Where such differences exist, only the levels of effect for the most
sensitive gender are presented.
AchE = acetylcholinesterase; Bd Wt = body weight; (C) = capsule; Cardio = cardiovascular; CEL = cancer effect level; d = day(s); (EEG) = electroencephalogram; (EMG) =
electromyogram; Endocr = endocrine; (F) = feed; F = female; FSH = follicle stimulating hormone; (G) = gavage; gastro = gastrointestinal; gd = gestation day; (GO) = gavage in oil;
(GW) = gavage in water; Hemato = hematological; LD50 = lethal dose, 50% kill; LOAEL = lowest-observed-effect level; M = male; MCV = mean corpuscular volume; mg/kg/day =
milligram/kilogram/day; mo = month(s); Musc/skel = musculoskeletal; NOAEL = no-observed-adverse-effect level; RBC = red blood cell(s); Resp = respiratory; (W) = water; wk =
week(s); x = times; yr = year(s)