Imagine if we had a readily available, sustainable and cost-effective way of reducing our greenhouse gas emissions? Sounds like a dream solution, right? On the surface, maybe. Our Food Safety scientists dove into the research to find out for sure.
Around the world, seaweed is used for a variety of purposes, from sushi to cosmetics to experimental bioplastics. But seaweed’s amazing uses don’t stop there. Recent research suggests it may also help reduce greenhouse gas emissions. And it’s to do with its ability to reduce how much livestock belch.
Just over half (53 per cent) of New Zealand’s greenhouse gas emissions come from agriculture, with almost 75 per cent of methane coming from the digestive systems of cattle.
But a chemical compound called bromoform, found in some types of seaweed, can inhibit the production of this methane. And not by a little. By a lot. When low levels of two types of seaweed, Asparagopsis taxiformis and Asparagopsis armata, were included in the feed of cattle and sheep, they were found to inhibit methane production by up to 98 per cent. However, in New Zealand’s grazing-based farm systems, where any seaweed would be fed as a once or twice daily supplement, the reductions are more like 20 per cent to 40 per cent.
But there’s a potential catch, with early scientific evaluations of bromoform classifying it as carcinogenic to humans. Naturally, public safety is of utmost importance, so the Ministry for Primary Industries (MPI) wanted to undertake a rigorous review of all scientific studies to evaluate the risks.
Enter PHF Science Food Safety scientists Peter Cressey and Abhishek Gautam. Together, they worked with experts from MPI (Jeff Fowles and Pravesh Tyagi), Lincoln University, (Charles Eason) and Tonkin+Taylor (Andrew Pearson) to review all of the information and research on bromoform, including how it carries over into products from the cows treated with it, such as milk.
They found that cancer risks from low doses of bromoform are likely to be negligible, and that, as an environmental inhibitor, it does not pose a significant risk to humans. This research was published in an international scientific journal.
Globally, further research and testing of bromoform is underway, including pre-market studies to inform the assessment and for regulatory consideration of bromoform use in New Zealand. The results will enable research to continue into what could be an effective and sustainable solution to help tackle New Zealand’s agricultural emissions.