BPA alternatives questioned
Replacements for BPA in plastics might cause similar reproductive problems in lab mice as the original ingredient does.
Bisphenol A (BPA) has been largely phased out of consumer products after a discovery 20 years ago that the ingredient had leached out of plastic cages used to house female mice in a laboratory, leading to a sudden increase in chromosomally-abnormal eggs in the animals.
But now the same research team that made that accidental discovery have found alternate bisphenols used to replace BPA in bottles, cups and other items may cause similar endocrine-disrupting problems in mice.
Their study, published today in Current Biology, called for more work to determine whether some bisphenols might be safer than others.
University of Auckland's Professor James Wright - director of the Centre for Green Chemical Science - said heat, microwaving, dishwasing and UV light contributed to breaking down polymers and releasing molecular BPA.
"A number of replacements for BPA have been developed. However, the safety and toxicity of these have been much less studied than it has for BPA. Just because a plastic is ‘BPA free’, it does not necessarily mean the replacement used is less toxic. Most likely the toxicity of the replacement has not been intensely studied."
University of Canterbury's Associate Professor Sally Gaw told Breakfast that BPA had originally been considered great for making rigid, clear plastic for items such as babies' bottles. But research had found BPA was turning up in people's urine, blood and amniotic fluid and there was evidence it was "found to interact with the body to sort of trigger a whole lot of hormonal pathways".
She said partly due to consumer backlash, BPA was withdrawn but had been replaced by a molecule "that looks very very similar". But due to those similarities, "it turns out unsurprisingly they interact with the body in a very similar way to BPA".
"I think we do need to consider all of our uses around plastic and the kind of exposures that we have," she said.
Scion's Lou Sherman - technical and service leader in the biopolymers and chemicals team - said it was important to note that not all plastics contain these BPA alternatives, Stuff reported.
"In general, plastics that are marked with the recycling codes 1 (PET, soft drink bottles), 2 (HDPE, milk bottles), 4 (LDPE, plastic bags), 5 (polypropylene), and 6 (polystyrene) are very unlikely to contain BPA or its alternatives."
"It is also important to note that even if a material does contain BPA or these alternatives, they will only pose a risk if they migrate from the packaging into the food at harmful levels."
The SMC gathered expert comments on the paper.
Quoted: Radio NZ
"Protecting our birds and other creatures from these introduced mammals is a hard, hard job and we cannot let it go or else we'll lose what's very special to this country."
Former Parliamentary Commissoner for the Environment Dr Jan Wright on the use of 1080 for pest control in New Zealand.
Alpine fault: special
The 300-year anniversary of the last time the Alpine Fault ruptured has been marked with a special issue of the New Zealand Journal of Geology and Geophysics.
Scheduled to be published last year - 300 years after the 1717 earthquake, the special issue was delayed by the 2016 Kaikōura earthquake, with research following the quake included in the special issue.
GNS Science’s Phaedra Upton, the chief guest editor of the special issue, said the Alpine Fault had a well-documented history of large earthquakes at fairly regular intervals, which meant there would be another one in the future. “Whatever we can learn about this fault and how it moves will help us understand and prepare for the next great earthquake.”
The 1717 rupture moved the Alpine Fault by about eight metres, so a similar quake could reshape the South Island, Newshub reported.
The series suggested a large event could strand about 10,000 people living in affected areas, along with several thousand tourists, the NZ Herald reported.
One of the featured studies, led by Tom Robinson from the UK's Durham University, suggested the number of tourists requiring evacuation by sea and air would be five times that of the 7.8 Kaikoura Earthquake in 2016, which was used as a guide in the modelling.
The Science Media Centre has several workshops coming up in October and November.
In October, our half-day video workshops will visit Christchurch and Dunedin. Produced in collaboration with Baz Caitcheon, the workshops focus on giving scientists the tools and skills to communicate their research in short videos aimed at an online audience.
The workshops are free to attend, but
limited to 15 places. This is a competitive application
process – the best applicants will be selected based on
the video concepts outlined in the application
• Christchurch, University of Canterbury
WED, 24th October, 9.00am – 1.00pm
• Dunedin, University of Otago
THURS, 25th October, 9.00am – 1.00pm
November SAVVY in Wellington
Our flagship media training course returns to Wellington for our fourth and final two-day Science Media SAVVY for the year.
• Wellington, Royal Society Te Apārangi
Our experienced facilitators provide a supportive environment for researchers to consider their work from different perspectives and find new ways to describe the value of their research to the public.
Ideally suited for
researchers with previous media experience seeking further
development of their skills, as well as beginners
anticipating media interest in their work.
Policy news & developments
Research grant recipients: $249m will be invested in 69 research projects through the 2018 round of the contestable Endeavour Fund.
Freshwater fish bill: A bill to better protect indigenous freshwater fish passed its first reading in Parliament this week.
Electricity price review: A discussion document for the first stage of the Electricity Price Review has been released, as the review enters its second stage.
Moths to combat plant: The EPA has approved an application that will allow two moths native to Europe to be imported to help combat horehound - a flowering weed from the mint family that damages farmers' crops.
Agricultural emissions: Former PM's chief science advisor's Sir Peter Gluckman's latest report aims to present a high-level perspective on what would be needed to achieve meaningful reductions in greenhouse gas emissions, and greater offsets, in the agricultural sector.
Digital fisheries monitoring: Fisheries Minister Stuart Nash has confirmed the next stage of digital monitoring across the wider commercial fishing fleet will begin in January 2019.
Stink bug monitoring: MPI has
promised to take tough action against cargo vessels believed
to be infested with brown marmorated stink bug during the
upcoming risk season.
This week on the NZ Conversation.
Women in sports: double standards a double fault
Marilyn Giroux, Jessica Vredenburg, Auckland University of Technology
Ivor Montagu: Communist aristocrat, Soviet
spy and activist filmmaker
Russell Campbell, Victoria University of Wellington
See more NZ-authored Conversation articles.