National monitoring data
The government of The Netherlands reported monitoring data on acephate in several crops (Table 11).
Table 11. Monitoring data on acephate in several crops in The Netherlands, 1991-1994.
|
Commodity |
Samples analyzed |
Number in which residues found1 |
Detection frequency, % |
Mean residues2, mg/kg |
|
Peaches |
379 |
16 |
4.2 |
0.04, <0.023 |
|
Nectarines |
401 |
19 |
4.7 |
<0.02, 0.023 |
|
Plums |
536 |
2 |
0.4 |
0.02 |
|
Grapes |
1335 |
18 |
1.3 |
0.02 |
|
Tomatoes |
330 |
4 |
1.2 |
0.02 |
|
Lettuce |
865 |
10 |
1.2 |
0.03, 0.053 |
|
Endive |
511 |
2 |
0.4 |
0.02 |
1 LOD = 0.02 mg/kg.2 For samples with residues below the LOD, half the LOD is taken for the calculation of the mean residues
3 Means for 1991-1993 and 1994 respectively
Market basket surveys
Market basket surveys for acephate and methamidophos were carried out in the USA in 1984 and 1985. From 26 to 62 commodities including fresh vegetables, fresh fruit, canned food, meat and dairy products were collected from 24 locations. Acephate and methamidophos were found at or above the limit of determination (0.01 mg/kg) in 6 and 7 commodities respectively (Table 12).
Table 12. Residues of acephate and methamidophos found at or above the limit of determination in market basket surveys in the USA, 1984 and 1985.
|
Commodity |
Residues, mg/kg |
Reference |
|
|
Acephate |
Methamidophos |
||
|
Cantaloupe |
0.03 |
0.02, 0.02, 0.03, 0.10 |
38 |
|
Celery |
0.01, 0.03, 0.04 |
0.04 |
|
|
Cucumbers |
- |
0.04, 0.06 |
|
|
Crisphead lettuce |
0.01, 0.09 |
0.02 |
|
|
Tomatoes |
0.01, 0.02 |
0.02, 0.02, 0.03, 0.04, 0.10, 0.17 |
|
|
Green sweet pepper |
0.06, 0.72 |
0.02, 0.03, 0.26 |
|
|
Canned snap beans |
0.01, 0.02 |
0.01 |
|
Farm gate to consumer studies
Farm gate to consumer studies were carried out on five crops in the USA in 1985 and 1986 (Lai, 1989a). Lettuce, snap beans, cauliflowers, Brussels sprouts and bell peppers were treated with acephate at the highest label use rate and monitored for residues from the time of harvest through typical commercial processes to the consumer. The results are given in Table 13.
Table 13. Residues of acephate and methamidophos in crisphead lettuce, snap beans, bell peppers cauliflowers and Brussels sprouts from farm gate to consumer, USA.
|
Application Year |
Description (Location) |
Average residues, mg/kg |
|||
|
Acephate |
% of field |
Methamidophos |
% of field |
||
|
0.63 kg ai/ha |
Whole head lettuce (field) |
0.30 |
100 |
0.02 |
100 |
|
+ 1.12 kg ai/ha |
Head + cap leaf (cooler) |
0.05 |
17 |
0.00 |
0 |
|
2 applications |
Head + cap leaf (distributor) |
0.06 |
20 |
0.00 |
0 |
|
PHI 21 days |
Head + cap (market) |
0.04 |
13 |
0.00 |
0 |
|
1985 |
Head + cap (supermarket shelf) |
0.03 |
10 |
0.00 |
0 |
|
0.84 kg ai/ha |
Fresh snap beans (field) |
0.29 |
100 |
0.06 |
100 |
|
2 applications |
Fresh snap beans (market) |
0.10 |
35 |
0.02 |
36 |
|
PHI 24 days |
Fresh snap beans (processing plant) |
0.13 |
46 |
0.03 |
55 |
|
1985 |
Canned snap beans |
0.05 |
18 |
0.02 |
36 |
|
Frozen snap beans in butter sauce |
0.03 |
11 |
0.00 |
0 |
|
|
1.5 kg ai/ha |
Bell peppers (field) |
3.8 |
100 |
0.52 |
100 |
|
7 applications |
Bell peppers (packing shed) |
2.8 |
74 |
0.43 |
83 |
|
PHI 9 days |
Bell peppers (distributor) |
2.7 |
71 |
0.45 |
87 |
|
1986 |
Bell peppers (supermarket) |
3.1 |
82 |
0.51 |
97 |
|
1.12 kg ai/ha |
Cauliflower head (field) |
0.80 |
100 |
0.10 |
100 |
|
6 applications |
Trimmed head (cooler) |
0.34 |
43 |
0.04 |
40 |
|
PHI 14 days |
Curd after coring (processor) |
0.33 |
41 |
0.04 |
40 |
|
1986 |
Curd after processing and freezing |
0.25 |
31 |
0.04 |
40 |
|
Processing waste |
0.73 |
91 |
0.10 |
95 |
|
|
1.12 kg ai/ha |
Fresh Brussels sprouts (field) |
1.85 |
100 |
0.03 |
100 |
|
6 applications |
Fresh sprouts after sorting |
0.79 |
43 |
0.02 |
67 |
|
PHI 14 days |
Sorting waste |
1.6 |
86 |
0.02 |
67 |
|
1986 |
Sprouts after blanching & freezing |
0.13 |
7 |
0.01 |
33 |
|
Processing waste |
9.4 |
508 |
0.15 |
500 |
|
