ARCHIVE FILE

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Interesting Pesticide Problems

I.R. Harradine, B.V.Sc., Veterinary Inspector, GRAFTON

CASE HISTORY ONE

On 23rd August, 1981 it was reported to me that a medium Aberdeen Angus yearling steer had a dieldrin level of 4.5ppm, being slaughtered at Grafton Abattoir on 29th June, 1981.

The owner was contacted on 27th August, 1981 and Form 1 detention notice issued at that time. The owner stated that the beast in question had been a calf fostered at birth to his Friesian house cow for 7 months. This beast had been for home kill and a little still remained in his freezer. The cow was still being hand milked and supplying five families (all relatives). The cow grazed a vacant block and also behind the owner's house in South Grafton. The two areas were surrounded by a total of twenty-five neighbouring backyards with garden refuse dumped over the fence from most of them.

The high dieldrin reading suggested milk concentration had occurred so the following samples were collected:

1. Freezer fat sample yielded 4.2 ppm dieldrin indicating we had the right beast. Some oxidation/reduction of dieldrin occurring in the freezer during the last two months.

2. Milk sample from the cow gave a reading of 2.7 ppm dieldrin on a butterfat basis.

3. Five soil and native grass (lawn clippings) samples gave readings ranging from 0.27 ppm to 99 ppm dieldrin and 1.0 ppm to 2.5 ppm DDT.

4. A freshly laid egg collected from one of the owner's free range chooks was found to contain 0.04 ppm dieldrin and 0.06 ppm DDT.

RESIDUE SOURCE

It appeared from these findings that the owner's house cow had been fed on dieldrin contaminated grass clippings kindly thrown over the fence by well intending neighbours. On questioning these neighbours whose grass clippings had been found to contain dieldrin they informed me dieldrin was used to control cutworms, black ants and other insects in their tidy suburban lawns, backyard trees and vegetable gardens.

This was not, however, the only source as a pasture sample from an open storm water drain running through the cow's paddocks yielded 0.27 ppm dieldrin. It was later established this dieldrin had come from a pest control operator washing down his truck into the street gutters two blocks away!

ACTION

Obviously the cow and all subsequent calves reared from it were placed in Form 2 detention. All neighbours were warned of dumping refuse over the fence in the cow's paddocks. The pest control operator was similarly warned by the local Pesticides Inspector.

PUBLIC HEALTH

On questioning those people (eighteen in all) who had been either eating the meat of the yearling or drinking the milk from the cow it was established that one mother of four young children had suffered a miscarriage, others notably the children complained of nausea, headaches and diarrhoea over the last month.

The Health Commission was contacted on these findings and the eighteen people involved blood sampled. Readings of up to 0.003 ppm dieldrin were found in the triglycerides of their blood. This was considered by them to be a 'safe' level.

CONCLUSION

The seriousness of pesticides in the environment and the ways they may move about are highlighted. In this case innocent well-meaning people uneducated in pesticide safety have jeopardised their own health and others.

A PARALLEL CASE

Recently another town owner on a 4.047 hectare area contaminated a crop of millet he was growing by irrigating from another open drain in South Grafton. The drain traverses approximately twenty properties before getting to this owner's block. A herd of eight cattle were residue affected as a result. The source of dieldrin upstream is suspected as coming from corn crops growing along its bank. The owner concerned has never used dieldrin but his property is now obviously contaminated. The environmental issues are worrying not to mention possible court cases arising from these findings.

CASE HISTORY TWO

On 25th June, 1980 a finding of 0.1 ppm Heptachlor Epoxide in a beast at slaughter traced back to a Dorrigo property. Owner informed and no action taken. On 18th September, 1980 at Macksville Abattoir another beast from the same owner is fat sampled and found to contain 3.3 ppm Heptachlor Epoxide and 0.4 ppm Oxychlordane.

Form 1 detention is issued and investigation commenced. Three hundred and ninety six cattle are involved on three separate properties. The owner is unable to remember where the traced back beast came from.

SOURCE

Heptachlor is a pesticide used primarily in the control of African Black Beetle and other pests in the growing of potatoes. Once potato crops are harvested cattle are allowed to graze the stubble and again later over oats or rye grass grown in the same paddock (sic). Cattle are fattened in this way as part of such an enterprise's normal routine. There are an estimated three hundred others doing exactly the same thing on the Dorrigo plateau with eighty percent affected by Black Beetle and using Heptachlor. Cattle attain their residue by ingestion of soil containing the Heptachlor. Heptachlor is applied by spinning mixed with fertilizer into the cultivated paddock before planting the potato buds.

INVESTIGATION

From 12th November, 1980 until 26th February, 1982 a total of eighty-four fat biopsy samples, sixty-five milk samples, forty-six soil samples and three pasture and potato samples have been collected from this owner's properties. These have been collected over twelve property visits. The estimated cost to the Pastures Protection Board and the Department would be $6,500. The owner, whose cost is estimated at $11,000, is still in quarantine. Dorrigo is some one hundred and fifty kilometres away from Grafton, the trip taking approximately two hours one way.

SOME FACTS

Heptachlor is not translocated into pastures so animals attain their residue from soil ingestion. This is exacerbated by drought conditions where an adult cow could be expected to assimilate more than one kilogram soil per day. The softer the sod the more soil consumed. The closer cattle graze to the ground the more soil they consume.

Residues in soils may remain there for many years and have been found in soils at a depth of twelve inches by core sampling. Some paddocks not used for potatoes since 1976 have substantial Heptachlor readings.

The half-life of Heptachlor in fat tissue of cattle has been quoted as fifty-two weeks but in my experience this varies greatly depending on the type of animal and many other factors:

Lactating dairy cow < three weeks

Steer or bullock maintaining weight > fifty-two weeks

Growing animal < fifty-two weeks.

Animals fluctuating in body weight seem to metabolise their residue more rapidly.

DECONTAMINATION

1. Agistment to clean areas. In view of the long half lives this is impractical due to expense.

2. Ploughing and burning. Deep ploughing could dilute residues and turn heavily contaminated topsoils under. Burning produces charcoal which can bind residues making them unavailable to the animal.

3. Fencing off contaminated areas to keep stock out.

CONCLUSION

At the end of January, 1982 there were seven owners involving nine hundred and eighty-four cattle in quarantine for Heptachlor residues in this area of the Grafton Board. Two of these owners have been in quarantine for more than twelve months. It is an emerging problem as Black Beetle infestation is increasing and more Heptachlor is being used.

The owner in quarantine is faced with problems of nil cash flow, increasing stock numbers with decreasing available clean land and a worried Veterinary Inspector who can offer his very little in terms of a solution.

A catch-22 situation exists in this area where an owner has to choose between cattle or potatoes. If he decides to grow potatoes he must use Heptachlor to control pests or his yield will be uneconomical. If he uses Heptachlor he cannot graze cattle for fear of quarantine.

The recent Pesticide Act has made it illegal to use Heptachlor for potato growing. Without any suitable alternatives at this point in time it would appear that a six million dollar industry will be lost. In fact since 1976 the area under potato cultivation has dropped from three thousand hectares to eight hundred hectares due to Black Beetle and worries about the use of Heptachlor.

COSTS OF FAT BIOPSY SAMPLING AT DORRIGO

1	WAGES, SUPERANNUATION, WORKERS COMPENSATION etc.	$150
2	TRAVELLING COSTS - 300 KILOMETRES	$97
3	EQUIPMENT
	ANTISEPTICS - ROXENOL, CETAVALON, IODINE	$30
	ANAESTHETICS- LIGNOCAINE
	ANTIBIOTICS - CHLORGENTIAN SPRAY
	EQUIPMENT DISPOSABLE - SCAPEL BLADES, COTTON WOOL, CATGUT, ALFOIL, SALT, SYRINGES, NEEDLES, SOAP, EARTAGS, LABELS, PLASTIC BAGS
	EQUIPMENT REUSABLE - SCISSORS, HANDLE, NEEDLE HOLDERS, NEEDLES, HAEMOSTATS, OYSTER TRAY, TABLE, EARTAG APPLICATOR, BUCKETS, SHOES, OVERALLS, PENS	$20
4	LABORATORY
	FREIGHT, ANALYSIS, SECRETARIAL	$180
5	OTHER COSTS
	TELEPHONE, DISCUSSION, SUPPLY	$50

AN APPROXIMATE TOTAL OF $527 per TEN BIOPSY FAT SAMPLES