Table 3.
RRs (95% CIs) for selected causes of death by lifetime chlorpyrifos exposure-days and intensity-weighted chlorpyrifos exposure-days among Agricultural Health Study applicators, 1993–2001.
| All causes of death
|
External causes of mortality (V01–Y98)
|
Suicide (X60–X84)
|
Non-motor-vehicle accidents (W00–X59)
|
Disease of the blood and blood-forming organs and certain disorders involving immune mechanisms (D50–D89)
|
Endocrine, nutritional and metabolic diseases (E00–E90)
|
Ischemic heart disease (I20–I25)
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chlorpyrifos exposure | No.a | RRb (95% CI) | No. | RR (95% CI) | No. | RR (95% CI) | No. | RR (95% CI) | No. | RR (95% CI) | No. | RR (95% CI) | No. | RR (95% CI) |
| Lifetime chlorpyrifos exposure-daysc | ||||||||||||||
| Nonexposed | 1,263 | 1.00 (referent ) | 141 | 1.00 (referent ) | 32 | 1.00 (referent) | 45 | 1.00 (referent) | 5 | 1.00 (referent) | 24 | 1.00 (referent) | 341 | 1.00 (referent) |
| ≤ 20.0 | 224 | 0.78 (0.67–0.92) | 27 | 0.74 (0.47–1.17) | 9 | 1.20 (0.53–2.70) | 8 | 0.58 (0.33–1.05) | 2 | 3.59 (0.56–23.22) | 3 | 0.89 (0.26–3.08) | 52 | 0.64 (0.46–0.88) |
| 20.1–56.0 | 183 | 0.94 (0.79–1.11) | 28 | 0.90 (0.57–1.42) | 5 | 1.01 (0.38–2.70) | 9 | 0.84 (0.48–1.46) | 1 | 2.76 (0.25–30.41) | 5 | 1.75 (0.57–5.39) | 53 | 0.99 (0.72–1.38) |
| ≥ 56.1 | 158 | 1.10 (0.91–1.33) | 32 | 1.69 (1.10–2.59) | 9 | 2.37 (1.03–5.48) | 14 | 2.20 (1.36–3.52) | 2 | 10.11 (1.48–68.95) | 3 | 1.82 (0.51–6.54) | 29 | 0.83 (0.54–1.26) |
| ptrend | 0.205 | 0.008 | 0.044 | 0.036 | 0.026 | 0.329 | 0.520 | |||||||
| Intensity-weighted chlorpyrifos exposure-daysd | ||||||||||||||
| Nonexposed | 1,263 | 1.00 (referent) | 141 | 1.00 (referent) | 32 | 1.00 (referent) | 45 | 1.00 (referent) | 5 | 1.00 (referent) | 24 | 1.00 (referent) | 341 | 1.00 (referent) |
| ≤ 78.8 | 167 | 0.84 (0.70–1.00) | 18 | 0.59 (0.33–1.04) | 7 | 1.18 (0.47–2.98) | 5 | 0.42 (0.20–0.89) | 0 | — | 3 | 1.30 (0.37–4.56) | 36 | 0.64 (0.44–0.93) |
| 78.9–318.1 | 159 | 0.88 (0.74–1.06) | 24 | 0.91 (0.56–1.47) | 4 | 0.87 (0.30–2.58) | 8 | 0.93 (0.53–1.63) | 0 | — | 2 | 1.07 (0.24–4.75) | 44 | 0.92 (0.65–1.30) |
| ≥ 318.2 | 168 | 1.00 (0.82–1.20) | 37 | 1.71 (1.13–2.60) | 9 | 2.05 (0.86–4.84) | 16 | 2.09 (1.30–3.36) | 3 | 12.68 (1.88–85.42) | 5 | 2.42 (0.75–7.82) | 33 | 0.78 (0.52–1.19) |
| ptrend | 0.005 | 0.005 | 0.101 | 0.034 | 0.003 | 0.146 | 0.316 | |||||||
Number of deaths; the reduced number of subjects included in the intensity-weighted exposure-days analysis is attributed to occasional missing data for some components of the intensity algorithm.
Relative risks adjusted for age at enrollment, sex, education, smoking, frequency of alcohol drinking during the 12 months before enrollment, and state of residence, and the four pesticides most highly correlated with chlorpyrifos (alachlor, carbofuran, fonofos, trifluralin). The reference category was applicators who were not exposed to chlorpyrifos. Applicators who did not provide information on chlorpyrifos days per year, years of use, and intensity level were excluded from this analysis.
Lifetime exposure-days = years of use × days per year. Cut points based on the distribution of all deaths among chlorpyrifos-exposed applicators.
Intensity-weighted exposure-days = years of use × days per year × intensity index. Cut points based on the distribution of all deaths among chlorpyrifos-exposed applicators.