5 ways to avoid lead exposure

Lead is one of the more prominent contaminants in agricultural operation, with serious risks to livestock and human health. Producers must be aware of the signs and impacts of lead exposure, as well as the methods to prevent it, and the steps involved to ensure it is not processed for human consumption.

Caption: Many lead sources can be found within old, deteriorating sheds. Ensure your sheds are maintained, destroyed or fenced off to avoid any possible exposure.

1. Understand the common ways lead exposure can occur

Lead sources can include:

• certain paints
• oil filters
• lead-light windows and linoleum
• old battery casings

NSW Department of Primary Industries veterinarian Dr. Liz Bolin warns that old battery casings can be brittle and easily breakable, with one broken battery potentially containing enough lead to kill over a dozen cattle.

Young cattle can be particularly at-risk. They are inquisitive, and can easily find, lick and chew materials that may contain or be exposed to high levels of lead. Aside from direct absorption from digestion, these materials can potentially lodge into ruminant stomachs, resulting in continuous poisoning.

“Recent cases involved young cattle and old car batteries, which could have been avoided by removing batteries from paddocks before any cattle had access,” said Dr. Bolin.

2. Know the symptoms to look out for and what to do next

Common early symptoms of high lead ingestion in your livestock include:

• teeth grinding 
• blindness
• muscle spasms
• lack of coordination
• rolling eyes
• head pressing
• tongue paralysis
• unresponsive demeanor
• reduced grazing

Animals that display symptoms must have a blood test conducted by a veterinarian, who will assist with further action. If lead poisoning is confirmed, a lead status will automatically be placed on your PIC through the NLIS database. The status is assigned by the Commonwealth or State Department, your vet or the Integrity Systems Company via the NLIS, depending on the type of status. You will be notified as soon as the status is implemented.

3. Know the impacts to your livestock and business

Ben Fahy, Manager of Livestock Traceability for Agriculture Victoria described one of the obvious first signs of lead poisoning as stock showing neurological signs and sudden death.

“Sudden death in livestock should be investigated immediately. Cattle that show neurological signs (changed behavior, unsteady gait, dullness) combined with sudden death can indicate possible lead toxicity. Properties that have old buildings with lead-based paint or forgotten batteries left in paddocks can allow cattle access to lead. Lead is sweet and salty to inquisitive livestock, so it’s extremely important that our producers are aware of these possible contaminants.”

In addition to the potential death of stock, producers are affected due to:

• loss of production
• affected by-products (such as milk)
• potential food safety issues
• processors being less likely to accept your livestock due to restrictions on how they can be marketed
• inability to sell stock/products

Cattle that are affected by lead are given a lead status that remains on your PIC whilst the cattle are still present on your property, creating heavy restrictions on the movement and sale of your livestock.

“Processors are often hesitant to take any cattle from a PIC that has a lead status. Processors are extremely careful to ensure that lead affected cattle are not processed or that unsuitable products do not enter the food chain.  Where cattle are consigned from a property that has a lead status, processors undertake extensive checks to ensure the individual cattle being processed are not affected by a lead status.  If cattle are untagged processors will have to assume that the untagged animal may have lead residues present and not process it.  Processors will always treat cattle from a property with a lead status with caution, to ensure safe products enter the food chain.” said Ben.

4. Understand how a lead status impacts your business

In some states a lead status is permanently applied to an individual animal’s NLIS (Cattle) tag and the PIC. Don’t risk it, a Property Risk Assessment can help mitigate the risk of lead poisoning to begin with and a permanent status.

A status is a description of possible contamination that can be assigned to properties, livestock or devices, so that animals can be traced along the supply chain for residue testing and food safety purposes.

While lead poisoning is defined as a blood lead level of over a certain threshold, any trace of lead in the bloodstream may result in the animal receiving a lead status.

There are two levels to a lead status, noting that processors are hesitant to take on any lead-affected animals, so will likely still turn your livestock away:

• PB1 – The animal’s lead levels are dangerously high, and the animal is unfit for human consumption.
• PB2 – Lead was detected but has been tested at low levels. Meat from animals with PB2 is suitable for human consumption but is often condemned.

Each state has its own regulations regarding lead statuses for livestock. In some, including Victoria, a lead status can only be removed once the animal is destroyed, with the status permanently classed on the individual animal and the PIC. However, other states allow for yearly animal checks, where blood tests can be conducted to see if lead is still present in the animal. For more information on your state’s requirements please visit your relevant state department.

5. Avoid impacts to your livestock and business by completing a Property Risk Assessment

Producers, especially those with LPA accreditation, should take care to undertake and document property risk assessments. By completing a risk assessment for your property, lead and other contaminants can be identified and a plan for excluding livestock and preventing exposure can be put in place.

The Risk Assessment includes checks that can be done to help mitigate a range of risks on your property. Some methods include:

• removing possible exposure sources
• fencing off all exposed areas, such as rubbish dumps and machinery holdings
• discarding deteriorating materials such as battery casing and peeling paints
• separating exposed livestock from healthy livestock
• completing a map of the property to make note of exposed areas and livestock

For more information on how to complete a Property Risk Assessment please follow the link here: LPA property risk assessment web page.

Animals that have been exposed to lead must be managed to ensure food safety and market access issues do not occur. If contamination is not prevented or notified and affected livestock are not taken care of, these products could enter the consumer market. To ensure livestock, business and industry safety, producers must take the necessary steps to ensure they stand by what they sell.