Spotlight on weedkiller
Use of popular weedkiller Roundup has been called into question again after a landmark court case in the US.
The San Francisco jury granted US$289 million
to a groundskeeper who said his lymphoma resulted from years of applying Monsanto’s trademarked Roundup herbicide,
which did not include adequate warning of its links to cancer.
The decision prompted Environment Minister Eugenie Sage to ask
the Environmental Protection Agency (EPA) to consider adding Roundup to a list of hazardous substances up for
Dr Fiona Thomson-Carter, general manager of New Zealand's EPA's Hazardous Substances Group, said there is "no change to
the science behind our current position, which is products containing glyphosate remain safe to use when you follow the
instructions on the products label".
New Zealand scientists argued the US ruling shouldn't prompt a knee-jerk ban of Roundup here.
"Herbicide use is seldom exposure to just one specific product - and the dose, duration, type, and frequency of exposure
is relevant to any potential risk," Associate Professor Brian Cox, a cancer epidemiologist at the University of Otago told the NZ Herald
"A sudden reaction to one case in one US law court, that has not yet gone to the appeal court, is not an appropriate
method of developing health policy in New Zealand."
There is debate over whether or not Roundup causes cancer. Massey University Centre for Public Health Research Professor
John Potter told The AM Show
that glyphosate — a key ingredient in Roundup - has officially been designated a "probable carcinogen" by the cancer
research arm of the World Health Organisation: the International Agency for Research on Cancer (IARC). He said councils
that use the weed killer on verges, greens and schools should reconsider their use, as should wider agriculture
businesses that use it.
However, Dr Belinda Cridge, a toxicologist from the University of Otago, told the SMC
the IARC definition means glyphosate may cause cancer, but there is no evidence of cause and effect and it may only do
so only under the right conditions and exposures. Red meat is also listed by IARC as a "probable carcinogen". She said
the IARC reviews are "based on good scientific evidence" but that "wider factors are critical to determining full risk".
She acknowledged: "it is very difficult to model and track all possible interactions" of the additives in Roundup and it
might be that the combination of these chemicals contributes to cancer — but this isn't something that's been tested
"It's important to consider the whole picture. Roundup isn’t, and has never been, a safe panacea for all weed control.
Scientists continue to learn more and more about this chemical and its effects. However, the alternative options aren’t
very appealing and many are much much worse for both people and the environment."
The SMC gathered expert reaction
to the court result and Environment Minister's response.
"It turns out it's kinda harder to [shoot something at the Sun] than you might think, because you've got to bring it
rest. Because the Earth is flying through space, you want to slow it down so it will fall towards the Sun.
So what they're doing is flying it to Venus and multiple encounters with the gravity of Venus will shape its orbit
cunningly using what's called a slingshot technique, until it flies closer and closer to the surface of the Sun."
Head of the University of Auckland's Physics Department
Bridge collapse in Italy
A motorway bridge collapse in Genoa this week killed at least 38 people and injured dozens.
This image, posted on twitter by @antoguerrara, shows the bridge after the collapse.
The 200m section of the bridge came tumbling down when one of the huge 90m-high support towers collapsed onto the rail
tracks, buildings and river below. Between 30 and 35 cars and three heavy vehicles were on the bridge at the time of the
collapse, the BBC reported
By Thursday (NZ time), the Italian Prime Ministers Giuseppe Conte had declared a 12-month state of emergency
in the region. The bridge - known as the Morandi bridge after its designer - is central to the country's motorway
system as it connects three ports and travelers from all over the country to the Italian Riviera
Structural engineer Antonio Brencich reportedly warned
there were problems with the bridge back in the 1990s and again in 2016, bringing to light a decades-long debate about
ageing Italian infrastructure. Engineering Professor Alessandro Palermo from the University of Canterbury knows Brencich
and he told Newstalk ZB
: "the bridge needed so much maintenance after just 20 years, it would have cost just as much to replace it".
The legacy of the bridge-building frenzy of the mid-20C means "there are a large number of reinforced concrete bridges
in Italy, Europe, USA, and Canada with the same age, which are suffering from corrosion of reinforcement and/or
pre-stressing tendon," according to Dr Mehdi Kashani
from the University of Southampton.
Structural engineer Dr. Demitrios Cotsovos from Heriot-Watt University told the UK SMC
that to prevent events like this in future, we need to find out what caused the Morandi bridge to collapse and use that
to monitor similar structures globally.
Professor Palermo told Newshub
the NZTA has a rigorous maintenance programme for bridges in New Zealand. "They have general inspections every two
years, and then they have a more detailed inspection after six years. That also depends on the condition of the bridge
[and] where the bridge is located."
The UK SMC asked experts to comment
on the disaster.
It'll be ultra-warm till 2022
As a heatwave tapers off in parts of the northern hemisphere, a new forecast system from UK and Dutch researchers has
predicted the years 2018 till 2022 are going to anomalously warm, with a greater chance of extreme temperatures.
On top of higher temperatures caused by climate change, the forecast suggests the world can expect 'extra warming' in
the next few years because of natural variability, the researchers found.
These natural changes occur as part of the cooling and heating of the planet's oceans, NIWA's chief scientist of
Climate, Atmosphere and Hazards Sam Dean told RNZ
"The last few years, we've had some really hot years, which were above that trend and this model is predicting that's
likely to carry on for a few more years," he said.
The forecast is based on a statistical model that provides reliable predictions of global mean air and sea surface
temperatures, taking into account external forces such as greenhouse gases and aerosols, along with natural variability.
Professor James Renwick from Victoria University of Wellington told Newshub
the new 'decadal' forecast system (which predicts climate in the coming two to 20 years) is at the forefront of climate
"If such forecasts could be made reliably they would clearly be of great value in many sectors: agriculture, energy,
emergency management, public health, etc. Most research is focused on using dynamical global climate models (GCMs, as
used for climate change simulations), where the ocean state is very carefully specified for the present day."
If the warming trend caused by greenhouse gas emissions continues, years like 2018 will be the norm in the 2040s, Prof
Renwick told the NZ Herald
, and would be classed as cold by the end of the century.