00:01We looked at the proportion of vehicle exhaust in urban areas and the proportion that was attributable to heavy vehicles
00:10and considered the population exposed, plant exposure, response functions, only for a small range of diseases that are causally associated
00:20with very strong confidence.
00:21So we really underestimated the impacts, to be honest, and calculated what that meant in terms of the population-weighted
00:29exposure of the Australian public.
00:31So, Claire, can you explain what some of the health impacts are of nitrogen oxide emissions, which are the emissions
00:37that come from heavy trucks?
00:39Yeah, so there's actually a complex mixture of pollutants, but the one that we used as the best surrogate to
00:45use for calculations is nitrogen dioxide.
00:48When we inhale what comes out of these exhaust pipes, they're tiny, tiny little combusted carbon particles in this combination
00:55of gases, and the particles are so small, they get from the bottom of our lungs into our bloodstream.
01:01Once they're in our bloodstream, they cause systemic inflammation across the whole body and sort of oxidative stress.
01:08So it's the opposite of an antioxidant.
01:10It puts our body under stress, and it's then associated with a very wide range of impacts.
01:16So premature mortality, lung cancer, cardiorespiratory diseases, diabetes, adverse birth outcomes, there's a lot of a huge range of impacts.
01:28We only included cardiorespiratory hospitalisations, childhood asthma, lung cancer, and premature death, because there's just decades of evidence and really
01:37robust dose response functions we could apply.
01:41But as I said, we've really underestimated.
01:43So how can someone be exposed to this to the point where it is damaging?
01:49So we know that, you know, if you're going for a run along the road, you might, a busy road,
01:53you might come into contract with it.
01:55You might work somewhere where there are high emissions around you.
01:58Yeah, so acute exposures, just even, you know, walking through a plume of vehicle exhaust, or if you're in a
02:05car driving behind, you know, a particularly dirty truck and you don't have the reticulation button on in your car,
02:12when you smell that diesel smell come inside, you're already getting respiratory or respiratory inflammation.
02:19Sometimes that can also go through to reduction of oxygen through to the heart, which can increase your risk of
02:25a cardiac arrest.
02:27And that's just short-term exposures.
02:29Long-term exposures, so people who live near a major road or go to a childcare centre or a school
02:34or work near major roads, are chronically exposed to higher levels.
02:39Now, that chronic exposure, which we measure sort of in annual levels, sets up, you know, your body under stress
02:46for a long period of time.
02:48So the chronic exposures, lung cancer, you know, it's even linked with vascular dementia and Alzheimer's and Parkinson's, over a
02:57period of time, it just makes our body less resistant and function is less resistant.
03:03You mentioned there, Claire, childcare centres.
03:06Did you look at children as a cohort specifically and the impact on them?
03:10We only managed to do that for childhood asthma.
03:13There is a much wider range of impacts, but there just isn't enough evidence for us to be able to
03:19do it robustly in the Australian population at the moment.
03:24This discussion paper comes ahead of the release of the federal government's heavy vehicle national law reform, which is due
03:31later this year.
03:32As a result of this discussion paper, are there recommendations that you're offering?
03:37Yeah, our biggest recommendation is when policymakers make decisions that will impact population exposure to these emissions, we would love
03:49if they included the health impacts.
03:53You know, when you make a cost benefit analysis, you consider what the costs and what the benefits.
03:57Now, I appreciate there are economic costs involved in removing dirty trucks off the roads or creating green urban corridors
04:07where there is, you know, big population density.
04:09I'm not saying whether or not we can afford to do that, but let's at least account for the health
04:15burden.
04:15Let's account for all that childhood asthma, the lifelong impacts, the hospital burden, which taxpayers pay for, the premature mortality.
04:23So let's accurately include those costs when we're making these policy decisions.
04:27Just in conclusion, Claire, if someone was listening, they might be quite concerned about where they're walking or where they're
04:34going about their daily life as a result of this discussion.
04:37Can we just be very clear that this is a discussion paper?
04:40Are you saying that one thing absolutely leads to another or more investigation is needed?
04:46No, no.
04:48The range of things we included are causally associated.
04:51So they are, you know, your risk is increased from the baseline, but the baseline risk is relatively low.
04:57On a population wide scale, it's important.
05:01And, you know, on an individual basis, if you have a child with asthma, they are going to be more
05:05susceptible to traffic emissions and those health impacts.
05:08Or without asthma, but you have a child and they're attending a childcare centre on a major road.
05:13Now, I appreciate a lot of them are built on major roads, and parents don't have easy decisions.
05:18I sent my own daughter to a childcare centre on a major road, and she subsequently now has asthma.
05:24It may or may not have been because of that.
05:26My point is there are things that can be done.
05:28You can have HEPA filters in rooms.
05:30You can consider your route when you're walking or going for a run in major traffic.
05:34If you can, take a road that's one further back in parallel.
05:40You know, and these are considerations policymakers need to include when they're making decisions.
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