Microplastics and nanoplastics are everywhere in our environment – including in our oceans and lakes, farmland, and even Arctic ice algae.

Microplastics have also been found inside of us – with studies detecting them in various tissues including in the lungs, blood, heart and placenta. Understandably, concern is rising about the potential risks of microplastics on our health.

However, while a growing body of research has focused on microplastics and nanoplastics, there’s still a lack of direct evidence that their presence in human tissues is harmful to our health – and it’s uncertain if they are related to particular diseases.

A new study has uncovered a correlation between microplastics and heart health, though. The researchers found that people who had detectable microplastics and nanoplastics in the plaque in their arteries had a higher risk of heart attack, stroke and death.

Heart health

The researchers looked at 257 people altogether. All of the patients were already undergoing preventative surgery to remove plaque from their carotid arteries (the main arteries that supply the brain with blood). This allowed the researchers to collect plaque samples and perform a chemical analysis. They then followed up with participants 34 months later.

Of the 257 participants, 150 were found to have the presence of microplastics and nanoplastics in their arterial plaque – mainly fragments of two of the most commonly used plastics in the world, polyethylene (used in grocery bags, bottles and food packaging) and polyvinyl chloride (used in flooring, cladding and pipes).

A statistical analysis of this data found that patients with microplastics and nanoplastics in their plaque had a higher risk of suffering a heart attack, stroke or death from any cause, compared with those who had no microplastics or nanoplastics in their plaque.

The researchers also analysed the macrophages (a type of immune cell that helps remove pathogens from the body) in the patients’ arteries. They found that participants who’d had microplastics and nanoplastics in their plaque also had evidence of plastic fragments in their macrophages.

They also looked at whether certain genes associated with inflammation (which can be a sign of disease) were switched on in the participants. They found that the participants who’d had microplastics and nanoplastics in their plaque also had signs of inflammation in their genes.

These results may suggest an accumulation of nanoplastics and microplastics in carotid plaque could partly trigger inflammation. This inflammation may subsequently change the way plaque behaves in the body, making it less stable and triggering it to form a blood clot – which can eventually block blood flow, leading to heart attacks and strokes.

Interestingly, the researchers also found the presence of nanoplastics and microplastics was more common in participants who had diabetes and cardiovascular disease. This raises a lot of questions which have yet to be answered – such as why microplastics were more common in these participants, and if there may be a correlation between other diseases and the presence of microplastics in the body.

Other health risks

This study only focused on patients who had carotid artery disease and were already having surgery to remove the build-up of plaque. As such, it’s unclear whether the findings of this study can be applied to a larger population of people.

However, it isn’t the first study to show a link between microplastics and nanoplastics with poor health. Research suggests some of this harm may be due to the way microplastics and nanoplastics interact with proteins in the body.

For example, some human proteins adhere to the surface of polystyrene nanoplastics, forming a layer surrounding the nanoparticle. The formation of this layer may influence the activity and transfer of nanoplastics in human organs.

Another study suggested that nanoplastics can interact with a protein called alpha-synuclein, which in mouse studies has been shown to play a crucial role in facilitating communication between nerve cells. These clumps of nanoplastics and protein may increase the risk of Parkinson’s disease.

My published PhD research in chicken embryos found that nanoplastics may cause congenital malformations due to the way they interact with a protein called cadherin6B. Based on the interactions myself and fellow researchers saw, these malformations may affect the embryo’s eyes and neural tube, as well as the heart’s development and function.

Given the fact that nanoplastics and microplastics are found in carotid plaque, we now need to investigate how these plastics got into such tissues.

In mice, it has been demonstrated that gut macrophages (a type of white blood cell) can absorb microplastics and nanoplastics into their cell membrane. Perhaps a similar mechanism is taking place in the arteries, since nanoplastics have been identified in samples of carotid plaque macrophages.

The findings from this latest study add to a growing body of evidence showing a link between plastic products and our health. It is important now for researchers to investigate the specific mechanisms by which microplastics and nanoplastics cause harm in the body.

Meiru Wang, Postdoctoral Researcher, Molecular Biology and Nanotoxicology, Leiden University

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

Hazel Keedle, Western Sydney University and Hannah Dahlen, Western Sydney University

In theory, pregnant women in Australia can choose the type of health provider they see during pregnancy, labour and after they give birth. But this is often dependent on where you live and how much you can afford in out-of-pocket costs.

While standard public hospital care is the most common in Australia, accounting for 40.9% of births, the other main options are:

• GP shared care, where the woman sees her GP for some appointments (15% of births)
• midwifery continuity of care in the public system, often called midwifery group practice or caseload care, where the woman sees the same midwife of team of midwives (14%)
• private obstetrician care (10.6%)
• private midwifery care (1.9%).

Given the choice, which model would women prefer?

Our new research, published BMC Pregnancy and Childbirth, found women favoured seeing the same health provider throughout pregnancy, in labour and after they have their baby – whether that’s via midwifery group practice, a private midwife or a private obstetrician.

Assessing strengths and limitations

We surveyed 8,804 Australian women for the Birth Experience Study (BESt) and 2,909 provided additional comments about their model of maternity care. The respondents were representative of state and territory population breakdowns, however fewer respondents were First Nations or from culturally or linguistically diverse backgrounds.

We analysed these comments in six categories – standard maternity care, high-risk maternity care, GP shared care, midwifery group practice, private obstetric care and private midwifery care – based on the perceived strengths and limitations for each model of care.

Overall, we found models of care that were fragmented and didn’t provide continuity through the pregnancy, birth and postnatal period (standard care, high risk care and GP shared care) were more likely to be described negatively, with more comments about limitations than strengths.

What women thought of standard maternity care in hospitals

Women who experienced standard maternity care, where they saw many different health care providers, were disappointed about having to retell their story at every appointment and said they would have preferred continuity of midwifery care.

Positive comments about this model of care were often about a midwife or doctor who went above and beyond and gave extra care within the constraints of a fragmented system.

The model of care with the highest number of comments about limitations was high-risk maternity care. For women with pregnancy complications who have their baby in the public system, this means seeing different doctors on different days.

Some respondents received conflicting advice from different doctors, and said the focus was on their complications instead of their pregnancy journey. One woman in high-risk care noted:

The experience was very impersonal, their focus was my cervix, not preparing me for birth.

Why women favoured continuity of care

Overall, there were more positive comments about models of care that provided continuity of care: private midwifery care, private obstetric care and midwifery group practice in public hospitals.

Women recognised the benefits of continuity and how this included informed decision-making and supported their choices.

The model of care with the highest number of positive comments was care from a privately practising midwife. Women felt they received the “gold standard of maternity care” when they had this model. One woman described her care as:

Extremely personable! Home visits were like having tea with a friend but very professional. Her knowledge and empathy made me feel safe and protected. She respected all of my decisions. She reminded me often that I didn’t need her help when it came to birthing my child, but she was there if I wanted it (or did need it).

However, this is a private model of care and women need to pay for it. So there are barriers in accessing this model of care due to the cost and the small numbers working in Australia, particularly in regional, rural and remote areas, among other barriers.

Women who had private obstetricians were also positive about their care, especially among women with medical or pregnancy complications – this type of care had the second-highest number of positive comments.

This was followed by women who had continuity of care from midwives in the public system, which was described as respectful and supportive.

However, one of the limitations about continuity models of care is when the woman doesn’t feel connected to her midwife or doctor. Some women who experienced this wished they had the opportunity to choose a different midwife or doctor.

What about shared care with a GP?

While shared care between the GP and hospital model of care is widely promoted in the public maternity care system as providing continuity, it had a similar number of negative comments to those who had fragmented standard hospital care.

Considering there is strong evidence about the benefits of midwifery continuity of care, and this model of care appears to be most acceptable to women, it’s time to expand access so all Australian women can access continuity of care, regardless of their location or ability to pay.

Hazel Keedle, Senior Lecturer of Midwifery, Western Sydney University and Hannah Dahlen, Professor of Midwifery, Associate Dean Research and HDR, Midwifery Discipline Leader, Western Sydney University

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