Mark Patrick Taylor, Macquarie University and Scott P. Wilson, Macquarie University

A recent study published in the prestigious New England Journal of Medicine has linked microplastics with risk to human health.

The study involved patients in Italy who had a condition called carotid artery plaque, where plaque builds up in arteries, potentially blocking blood flow. The researchers analysed plaque specimens from these patients.

They found those with carotid artery plaque who had microplastics and nanoplastics in their plaque had a higher risk of heart attack, stroke, or death (compared with carotid artery plaque patients who didn’t have any micro- or nanoplastics detected in their plaque specimens).

Importantly, the researchers didn’t find the micro- and nanoplastics caused the higher risk, only that it was correlated with it.

So, what are we to make of the new findings? And how does it fit with the broader evidence about microplastics in our environment and our bodies?

What are microplastics?

Microplastics are plastic particles less than five millimetres across. Nanoplastics are less than one micron in size (1,000 microns is equal to one millimetre). The precise size classifications are still a matter of debate.

Microplastics and nanoplastics are created when everyday products – including clothes, food and beverage packaging, home furnishings, plastic bags, toys and toiletries – degrade. Many personal care products contain microsplastics in the form of microbeads.

Plastic is also used widely in agriculture, and can degrade over time into microplastics and nanoplastics.

These particles are made up of common polymers such as polyethylene, polypropylene, polystyrene and polyvinyl chloride. The constituent chemical of polyvinyl chloride, vinyl chloride, is considered carcinogenic by the US Environmental Protection Agency.

Of course, the actual risk of harm depends on your level of exposure. As toxicologists are fond of saying, it’s the dose that makes the poison, so we need to be careful to not over-interpret emerging research.

A closer look at the study

This new study in the New England Journal of Medicine was a small cohort, initially comprising 304 patients. But only 257 completed the follow-up part of the study 34 months later.

The study had a number of limitations. The first is the findings related only to asymptomatic patients undergoing carotid endarterectomy (a procedure to remove carotid artery plaque). This means the findings might not be applicable to the wider population.

The authors also point out that while exposure to microplastics and nanoplastics has been likely increasing in recent decades, heart disease rates have been falling.

That said, the fact so many people in the study had detectable levels of microplastics in their body is notable. The researchers found detectable levels of polyethylene and polyvinyl chloride (two types of plastic) in excised carotid plaque from 58% and 12% of patients, respectively.

These patients were more likely to be younger men with diabetes or heart disease and a history of smoking. There was no substantive difference in where the patients lived.

Inflammation markers in plaque samples were more elevated in patients with detectable levels of microplastics and nanoplastics versus those without.

And, then there’s the headline finding: patients with microplastics and nanoplastics in their plaque had a higher risk of having what doctors call “a primary end point event” (non-fatal heart attack, non-fatal stroke, or death from any cause) than those who did not present with microplastics and nanoplastics in their plaque.

The authors of the study note their results “do not prove causality”.

However, it would be remiss not to be cautious. The history of environmental health is replete with examples of what were initially considered suspect chemicals that avoided proper regulation because of what the US National Research Council refers to as the “untested-chemical assumption”. This assumption arises where there is an absence of research demonstrating adverse effects, which obviates the requirement for regulatory action.

In general, more research is required to find out whether or not microplastics cause harm to human health. Until this evidence exists, we should adopt the precautionary principle; absence of evidence should not be taken as evidence of absence.

Global and local action

Exposure to microplastics in our home, work and outdoor environments is inevitable. Governments across the globe have started to acknowledge we must intervene.

The Global Plastics Treaty will be enacted by 175 nations from 2025. The treaty is designed, among other things, to limit microplastic exposure globally. Burdens are greatest especially in children and especially those in low-middle income nations.

In Australia, legislation ending single use plastics will help. So too will the increased rollout of container deposit schemes that include plastic bottles.

Microplastics pollution is an area that requires a collaborative approach between researchers, civil societies, industry and government. We believe the formation of a “microplastics national council” would help formulate and co-ordinate strategies to tackle this issue.

Little things matter. Small actions by individuals can also translate to significant overall environmental and human health benefits.

Choosing natural materials, fabrics, and utensils not made of plastic and disposing of waste thoughtfully and appropriately – including recycling wherever possible – is helpful.

Mark Patrick Taylor, Chief Environmental Scientist, EPA Victoria; Honorary Professor, School of Natural Sciences, Macquarie University and Scott P. Wilson, Research Director, Australian Microplastic Assessment Project (AUSMAP); Honorary Senior Research Fellow, School of Natural Sciences, Macquarie University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This week’s ABC Four Corners episode Pain Factory highlighted that our health system is failing Australians with chronic pain. Patients are receiving costly, ineffective and risky care instead of effective, low-risk treatments for chronic pain.

The challenge is considering how we might reimagine health-care delivery so the effective and safe treatments for chronic pain are available to millions of Australians who suffer from chronic pain.

One in five Australians aged 45 and over have chronic pain (pain lasting three or more months). This costs an estimated A$139 billion a year, including $12 billion in direct health-care costs.

The most common complaint among people with chronic pain is low back pain. So what treatments do – and don’t – work?

Opioids and invasive procedures

Treatments offered to people with chronic pain include strong pain medicines such as opioids and invasive procedures such as spinal cord stimulators or spinal fusion surgery. Unfortunately, these treatments have little if any benefit and are associated with a risk of significant harm.

Spinal fusion surgery and spinal cord stimulators are also extremely costly procedures, costing tens of thousands of dollars each to the health system as well as incurring costs to the individual.

Addressing the contributors to pain

Recommendations from the latest Australian and World Health Organization clinical guidelines for low back pain focus on alternatives to drug and surgical treatments such as:

• education
• advice
• structured exercise programs
• physical, psychological or multidisciplinary interventions that address the physical or psychological contributors to ongoing pain.

Two recent Australian trials support these recommendations and have found that interventions that address each person’s physical and psychological contributors to pain produce large and sustained improvements in pain and function in people with chronic low back pain.

The interventions have minimal side effects and are cost-effective.

In the RESOLVE trial, the intervention consists of pain education and graded sensory and movement “retraining” aimed to help people understand that it’s safe to move.

In the RESTORE trial, the intervention (cognitive functional therapy) involves assisting the person to understand the range of physical and psychological contributing factors related to their condition. It guides patients to relearn how to move and to build confidence in their back, without over-protecting it.

Why isn’t everyone with chronic pain getting this care?

While these trials provide new hope for people with chronic low back pain, and effective alternatives to spinal surgery and opioids, a barrier for implementation is the out-of-pocket costs. The interventions take up to 12 sessions, lasting up to 26 weeks. One physiotherapy session can cost $90–$150.

In contrast, Medicare provides rebates for just five allied health visits (such as physiotherapists or exercise physiologists) for eligible patients per year, to be used for all chronic conditions.

Private health insurers also limit access to reimbursement for these services by typically only covering a proportion of the cost and providing a cap on annual benefits. So even those with private health insurance would usually have substantial out-of-pocket costs.

Access to trained clinicians is another barrier. This problem is particularly evident in regional and rural Australia, where access to allied health services, pain specialists and multidisciplinary pain clinics is limited.

Higher costs and lack of access are associated with the increased use of available and subsidised treatments, such as pain medicines, even if they are ineffective and harmful. The rate of opioid use, for example, is higher in regional Australia and in areas of socioeconomic disadvantage than metropolitan centres and affluent areas.

So what can we do about it?

We need to reform Australia’s health system, private and public, to improve access to effective treatments for chronic pain, while removing access to ineffective, costly and high-risk treatments.

Better training of the clinical workforce, and using technology such as telehealth and artificial intelligence to train clinicians or deliver treatment may also improve access to effective treatments. A recent Australian trial, for example, found telehealth delivered via video conferencing was as effective as in-person physiotherapy consultations for improving pain and function in people with chronic knee pain.

Advocacy and improving the public’s understanding of effective treatments for chronic pain may also be helpful. Our hope is that coordinated efforts will promote the uptake of effective treatments and improve the care of patients with chronic pain.

Christine Lin, Professor, University of Sydney; Christopher Maher, Professor, Sydney School of Public Health, University of Sydney; Fiona Blyth, Professor, University of Sydney; James Mcauley, Professor of Psychology, UNSW Sydney, and Mark Hancock, Professor of Physiotherapy, Macquarie University

This article is republished from The Conversation under a Creative Commons license. Read the original article.