Table 2.
Summary of house-dust herbicide detection and concentrations for cases and controls, the Northern California Childhood Leukemia Study, 2001–2007
| Childhood ALL Cases (n=252) | Controls (n=306) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Detection Limitb | Detected | Not detected | Missingc | Arithmetic Meanb | Detected | Not detected | Missingc | Arithmetic Meanb | p-valued | |
| Analytea | (%) | (%) | (%) | (SD) | (%) | (%) | (%) | (SD) | ||
| Alachlore, f | 4.7 | 25 (10) | 226 (90) | 1 (<1) | 2.9 (12.5) | 34 (11) | 272 (89) | 0 (0) | 4.1 (19.4) | 0.66 |
| Metolachlore, f | 67.6 | 0 (0) | 251 (100) | 1 (<1) | n/a | 2 (<1) | 304 (99) | 0 (0) | 0.5 (5.6) | 0.2 |
| Bromoxynile, g | 0.8 | 15 (6) | 232 (92) | 5 (2) | 0.2 (0.9) | 25 (8) | 275 (90) | 6 (2) | 0.6 (4.0) | 0.31 |
| Bromoxynil octanoatee, h | 250.4 | 1 (<1) | 250 (99) | 1 (<1) | 1.0 (15.8) | 1 (<1) | 302 (99) | 3 (1) | 1.0 (17.3) | 0.89 |
| Pebulatee, f | 19.7 | 1 (<1) | 250(99) | 1 (<1) | 0.1 (1.2) | 2 (<1) | 304(99) | 0 (0) | 0.2 (2.5) | 0.68 |
| Butylated, f | 81.2 | 0 (0) | 251(99) | 1 (<1) | n/a | 1 (<1) | 305(100) | 0 (0) | 0.3 (4.6) | 0.37 |
| Cyanazinee, f | 65.1 | 8 (3) | 243 (97) | 1 (<1) | 11.8 (93.9) | 4 (1) | 302 (99) | 0 (0) | 13.0 (153.5) | 0.13 |
| Prometryne, f | 7.2 | 2 (<1) | 249 (99) | 1 (<1) | 0.1 ( 1.1) | 2 (<1) | 301 (98) | 3 (1) | 0.4 (5.6) | 0.85 |
| Simazinee, f | 0.8 | 222 (88) | 29 (12) | 1 (<1) | 28.7 (39.3) | 282 (92) | 24 (8) | 0 (0) | 56.8 (247.5) | 0.14 |
| Ethalfluraline, f | 54.5 | 0 (0) | 251 (100) | 1 (<1) | n/a | 1 (<1) | 305 (100) | 0 (0) | 0.2 (3.1) | 0.37 |
| Pendimethaline, f | 15.4 | 15 (6) | 221 (88) | 16 (6) | 22.1 (224.7) | 20 (7) | 269 (88) | 17 (6) | 28.9 (199.4) | 0.8 |
| Trifluralinf | 0.2 | 156 (62) | 95 (38) | 1 (<1) | 2.3 (5.4) | 180 (59) | 126 (41) | 0 (0) | 3.4 (12.2) | 0.42 |
| MCPAg | 1.4 | 35 (14) | 212 (84) | 5 (2) | 4.6 (27.3) | 53 (17) | 277 (81) | 6 (2) | 5.5 (15.9) | 0.27 |
| Mecopropf, g, i | 2.2 | 215 (85) | 32 (13) | 5 (2) | 149.2 (466.7) | 246 (80) | 54 (18) | 6 (2) | 165.7 (472.9) | 0.11 |
| 2,4-Dg | 3.8 | 236 (94) | 11 (4) | 5 (2) | 383.3 (804.0) | 296 (97) | 3 (1.0) | 7(2) | 831.4 (6041.7) | 0.01 |
| Chlorthalg, j | 0.2 | 101 (40) | 150 (60) | 1 (<1) | 2.2 (7.0) | 94 (31) | 212 (69) | 0 (0) | 5.7 (57.6) | 0.02 |
| Dicambag | 1.05 | 60 (24) | 187 (74) | 5 (2) | 4.0 (11.7) | 92 (30) | 208 (68) | 6(2) | 5.6 (17.3) | 0.1 |
Abbreviations: ALL, acute lymphocytic leukemia; SD, standard deviation; %, percentage (do not always add up to 100% due to rounding)
a
Names according to the International Organization for Standardization (ISO)
b
Analyte concentration in ng/g of dust
c
Missing due to insufficient dust or interferences in the chemical analyses
d
P-value derived from Fisher’s exact test comparing % detected between cases and controls
e
Primarily agricultural or professional-use herbicide
f
Hexane-acetone extraction method
g
Acid extraction method
h
Acid extraction method
i
Also known as MCPP
j
Also known as DCPA or dacthal