ONGOING spray drift complaints throughout South Australia have led to farmers being urged to use very coarse and extremely coarse droplets in summer spraying of translocated herbicides.
Mid North consultant Mick Faulkner said that while there appeared to be some improvement in broadacre spraying practices over the past summer, damage had again occurred in the Clare and Barossa Valleys and the Riverland.
“This occurred despite the threat of losing valuable chemicals and increased spraying buffer zones,” he said.
“Farmers were also largely unaware that herbicides could travel for up to 100 kilometres when inversion layers are present and small droplets are produced by spray nozzles.”
As a result of the problems, the Mid North High Rainfall Zone Group and Hart Fieldsite Group undertook a GRDC-funded project in February in collaboration with the Mid North Spray Drift Committee, the Clare Wine Grape Growers Association and Peter Cousins Consulting.
The project investigated the control of summer weeds using larger spray droplets under more adverse daytime summer weather conditions.
Trials manager Roy Rogers said the trials were in response to farmers depositing pesticides, causing damage to other agricultural industries, homes and gardens and environmentally sensitive areas.
“As farmers we have been causing damage to others and if we don’t get it right we leave governments with little choice but to tighten-up regulations, ” he said.
“The drift issue is continuing, particularly in the Mid North where we have vineyards within 100 kilometres of where there is a lot of summer spraying. Not having a vineyard within close proximity is not a reliable guide to the risk of damage from summer spraying.
“We’ve got these pressures and responsibilities and it’s getting to the point where unless growers use these chemicals more safely, they might lose them.”
* More in the Stock Journal’s April 19 edition
• Woodsmoke: Evidence of genetic damage in human babies and behavioural problems
from Dorothy L Robinson
Harvard Uni has recently published a very informative study linking BaP (*
benzo[a]pyrene) *exposure to behavioural problems
This is a really informative study because
1) Pregnant women (non smokers, 3rd trimester of pregnancy) carried
backpacks for a couple to days to measured PAH (polycyclic aromatic
hydrocarbons) exposure. BaP is one of the more toxic PAHs.
2) Genetic damage from BaP exposure in the babies was measured by the
presence of adducts specific to BaP in umbilical cord blood. 41% of
children had detectable BaP adducts.
3) These children were estimated to be* 4 times more likely to have
attention problems and 2.5 times more likely to have ADHD* than other
children.
The proportion of all children with behavioural problems were:
Anxious/Depressed 6.32%
Attention Problems 6.72%
Anxiety Problems (DSM) 9.48%
Attention Deficit Hyperactivity Problems (DSM) 7.91%
So, with the 41% of children having detectable BaP adducts in cord blood,
and these children being 2 to 4 times more likely to have behavioural
problems than children without BaB adducts, BaP exposure appears to
represent a major factor increasing the risk for these problems – more info
– http://woodsmoke.3sc.net/pah
Although BaP is also in cigarette smoke, burning 1 kg of wood in an
Australian domestic heater releases 820,000 ng of BaP – as much as in the
smoke of 27,000 cigarettes – see
http://woodsmoke.3sc.net/wood-vs-cigarette-smoke
Burning 1 kg of wood also emits 900,000 ng of another chemical
dibenz[a,h]anthracene,
with an even higher carcinogenic potency (1.1 times BaP). Cigarette smoke
does not contain a lot of this chemical (4 ng/cigarette).
The Harvard Uni study explains that ambient BaP levels were less than 0.5
ng/m3 – similar to wintertime levels of 0.46 ng/m3 in Sydney, 0.30 in
Newcastle, 1.12 in Tumut and Cooma, 1.30 in Armidale. Average summer
measurements were .02 to 0.09 u/m3.
I’ve attached the PAH section of the US National Toxicology Program, Report
on Carcinogens, Eleventh Edition (2005), which states: “The primary source
of PAHs in air is the incomplete combustion of wood and fuel for
residential heating.”
In Australia, the National Pollutant Inventory show that the largest
single-source of PAH emissions is domestic wood heaters – see
http://woodsmoke.3sc.net/pah
The NPI reports PAH in terms of BaP-equivalent. Most are less potent than
BaP. The exception is dibenz[a,h]anthracene. Burning 1 kg of wood
produces 900,000 ug of dibenz[a,h]anthracene, compared to 4 ug from the
average cigarette.
An earlier study related PAH exposure of the pregnant mothers to IQ of the
children when they started school. PAH exposure above 2.26 n/m3
(considered high in this study) was associated with a 5 point reduction in
IQ when the children started school. Unfortunately, exposure of 2.2 6
ng/m3 doesn’t seem particularly high for areas where wood heater use is
common. Armidale’s average wintertime PAH measurements ( 8.62 ng/m3) were
almost 4 times higher than average PAH exposure of the women in this study.
Studies of woodsmoke exposure usually involve cooking smoke in developing
countries. A significant relationship between woodsmoke exposure and
reduced IQ on starting school was noted for Guatemala – prenatal maternal
exposure to woodsmoke and poorer performance in markers for IQ among
school-age children
One possible solution for Australia might be for councils to subsidize HEPA
filters for pregnant women. They filter out the toxic particles and reduce
the risk of heart disease (
http://www.sciencedaily.com/releases/2011/01/110121144009.htm), so should
also remove the toxic PAH and other chemicals that are adsorbed on them.
This could also provide a useful educational message that woodsmoke is
harmful.
The NSW State Government recently released an economic report showing that
woodsmoke is an $8 billion health problem just in NSW – see
http://www.environment.nsw.gov.au/woodsmoke/smokecontrolopts.htm
Given the above facts – the estimated $8 billion health cost of woodsmoke,
and that PAH exposure is linked to genetic damage in babies, reduced IQ on
starting school and behavioural problems – and that domestic wood heating
is the largest single source of PAH in Australia – is there any interest in
this group is trying to combat the problem? If so, please reply to email
and ideally also cc to adorre AT gmail DOT com.
There are a lot of toxic chemicals to avoid. However, woodsmoke is one of
the most serious because of the large quantities in our air, and because
most people who buy and install wood heaters do so in response to slick
advertising that falsely leads unsuspecting consumers to believe that
woodsmoke is harmless. It would be great to hear from other people who
think something should be done about about this problem.
Regards,
Dorothy
Attachment(s) from Dorothy L Robinson
1 of 1 File(s)
US_Health_human_services_Report_on_Carcinogents_PAH_v11.pdf
