TABLE 2—
Human Testing of Pesticides, Study Objectives, and Additional Design Considerations
| Pesticide | Study Objectives | Variables Measured (including data not specified in study objectives) | Statistical Test Applied to Variable | Findings, Conclusion(s) |
| Aldicarb | Determine general tolerance to various doses | Vital signs, pulmonary function, salivation, pupil size, ECG, clinical signs (nausea, vomiting, sweating, diarrhea, abdominal cramps, slurred speech) | ANCOVA for bolded items at left, none specified for others | 45% reduction in AChE at highest dose, “clinical no effect level . . . is . . . 0.05 mg/kg”11 |
| Determine effect on plasma and RBC AChE | Plasma and RBC AChE | ANCOVA | ||
| Dichlorvos, single dose | Assess effect on RBC AChE | RBC AChE | Paired t test pre vs post dose means | Significant effect at day 5,6, and 14 in group analysis. Five of 6 had significant effect on individual analysis |
| Symptoms reported by volunteers | None specified | NOEL established at 70 mg (approximately 1 mg/kg). | ||
| Dichlorvos, 7 mg daily for 21 days | Assess effect on RBC AChE | RBC AChE | Repeated measures ANOVA | Significant reduction on all dates after 10 days of dosing. |
| Symptoms reported by volunteers | None specified | “Results from this study can unequivocally establish a NOEL at 7 mg dichlorvos per day . . . following repeat administration for 21 days.”6 | ||
| Dichlorvos, 2 phase | Assess effect on RBC AChE after single and multiple doses | RBC AChE | Paired t test pre vs post dose means | 2 of 6 subjects withdrawn because of AChE depressions, 2 more met withdrawal criteria on last day. Significant reductions in AChE from day 5–33 after 15 days of dosing. |
| Symptom form completed by volunteer | None specified | “NOEL established at or close to 21 mg . . . approximately 0.3 mg/kg . . .”5 | ||
| Azinphos methyl | Establish recommended daily intake for chronic dietary exposure | None | None specified | |
| Determine NOEL for plasma and RBC AChE | Plasma and RBC AChE | Repeated measures ANOVA, paired t placebo vs agent at each time | Significant increase in inhibition (paired t) at 4 of 24 time points for plasma AChE and 2 of 24 time points for RBC AchE.a | |
| Conduct risk assessment and obtain information for biological monitoring | Adverse events coded using World Health Organization terminology | None specified | Repeat doses of 0.25 mg/kg were safe | |
| Chlorpyrifos | Determine NOEL for RBC AChE | RBC AChE | ANOVA | NOEL for signs and symptoms was 2.0 mg/kg body weight |
| Signs and symptoms coded using COSTART Adverse Event Dictionary, 5th Edition | None specified |
Note. ANCOVA = analysis of covariance; ANOVA = analysis of variance; NOEL = no observable effect level; RBC = red blood cell; AChE = acetylcholinesterase; ECG = electrocardiogram.
aFor each of the 22 time points, the azinphos methyl group had greater inhibition of plasma AChE than placebo; data not analyzed or commented on by investigators. For RBC AChE, 6 of the 12 values were higher.