(Press-News.org) Higher levels of ozone from air pollution are linked to an increased risk of developing fibroids among Black American women according to a large study published today (Friday) in Human Reproduction [1], one of the world's leading reproductive medicine journals.
Fibroids are non-cancerous growths that develop in and around the womb. They are diagnosed in 25-30% of pre-menopausal women, but the true incidence is thought to be between 70-80%. Many fibroids do not cause symptoms but when they do, they are one of the main reasons women are admitted to hospital for inpatient care. Symptoms can include heavy or painful periods, stomach and back pain, constipation, frequent need to urinate, and pain or discomfort during sex. In some cases they can affect fertility and pregnancy. Women of African-Caribbean origin are diagnosed with fibroids two to three times more often than white women, and they tend to experience earlier onset of symptoms and more severe disease.
Previous research has shown that Black people are exposed to higher levels of air pollution than white people in the USA but, until now, there has been no investigation into the association between air pollution and fibroids in Black women.
The study published today investigated concentrations of three environmental pollutants in the air in 56 US metropolitan areas between 1997 and 2011: particulate matter smaller than 2.5 microns (PM2.5), nitrogen dioxide (NO2) and ozone (O3). The 21,998 premenopausal Black women who lived in these areas and were included in the research were part of the ongoing Black Women's Health Study. They answered questionnaires every two years and were followed up until 2019.
During the 14-year follow-up period, 6238 (28.4%) of women reported having fibroids diagnosed by a doctor and confirmed by ultrasound or surgery. Average (median) concentrations of ozone were 36.9 parts per billion (ppb), with a range of 25.4 to 55 ppb.
After adjusting for factors that could affect the results, such as education, smoking, body mass index, diet and whether or not the women had been pregnant, the researchers found that the risk of self-reported fibroids increased with increasing levels of ozone in the atmosphere, but not with PM2.5 or NO2.
Ozone was linked to a 35% increased risk of fibroids among the 20% of women exposed to the highest levels of ozone (42-55 ppb) - a rate of 33.6 cases per 1000 women, compared with the 20% exposed to the lowest levels (25-33 ppb) - a rate of 31.4 cases per 1000 women [2]. The association was stronger among women aged less than 35 years and for women who had been pregnant.
First author of the study, Dr Amelia Wesselink, an Assistant Professor in the Department of Epidemiology at Boston University School of Public Health (Massachusetts, USA), said: "We were surprised to see an association for ozone but not for PM2.5 and NO2. The mechanisms that we think could explain the association between ozone and fibroids are also relevant for the other pollutants, so this was an unexpected finding. It may reflect that there is a mechanism unique to ozone that we are missing, but it might also mean that there is factor that we've not been able to measure that could affect the results. For example, we were unable to account for vitamin D exposure and vitamin D deficiency is a suspected risk factor for fibroids."
Biological mechanisms that might be involved in the link between ozone and fibroids include an immune inflammatory response; oxidative stress (an imbalance between molecules in the body, leading to cell and DNA damage); high blood pressure that could lead to fatty deposits on artery walls; and activation of the body's stress response.
Dr Wesselink said that the increased risk of fibroids among Black women was not explained by known risk factors, or by socioeconomic status, or access to or quality of health care.
"We are still trying to figure out what specific exposures explain this disparity. Possible explanations that are under investigation include stress throughout life due to systematic oppression and racism; vitamin D deficiency; and environmental factors like air pollution, which we know are inequitably distributed across populations in the United States.
"There have now been three studies suggesting a link between air pollution and fibroids, but ours is the first to show this in Black women. Because Black women are inequitably exposed to air pollution, these findings have important implications for racial disparity in fibroids."
The study has some limitations. These include the way exposure to air pollution was measured; the fact that women reported doctors' diagnoses of fibroids, which could have led to an under-estimation of the problem; and that the researchers were unable to measure factors that could affect the results, such as vitamin D exposure.
Dr Wesselink said: "Vitamin D deficiency is a key hypothesis that is under investigation to explain the racial disparity in fibroids. It is certainly possible that our findings could be explained by vitamin D. This is something that should be considered in future work on this topic."
She concluded: "Further research and additional funding is needed to understand the role of air pollution in fibroid development. For instance, a prospective, ultrasound-based study could identify fibroids, regardless of whether or not they are causing symptoms that lead to women seeking medical care. In addition, we need to consider the role of other features in the physical and built environment in the development of fibroids; factors such as environmental noise, access to green spaces and other neighbourhood exposures."
INFORMATION:
[1] "A prospective cohort study of ambient air pollution exposure and risk of uterine leiomyomata", by Amelia K. Wesselink et al. Human Reproduction journal. doi:10.1093/humrep/deab095
[2] These rates have not been adjusted for various factors that could affect the results.
The need to evacuate an intensive care unit (ICU) or operating theatre complex during a fire or other emergency is a rare event but one potentially fraught with difficulty: not only is there a risk that patients may come to significant harm but also that staff may be injured and unable to work.
Therefore, the Association of Anaesthetists and the Intensive Care Society are today publishing new 2021 guidelines regarding fire safety and emergency evacuation of ICUs and operating theatres in Anaesthesia (a journal of the Association of Anaesthetists).
These guidelines ...
LA JOLLA, CA--A family of proteins that sense mechanical force--and enable our sense of touch and many other important bodily functions--also are essential for proper root growth in some plants, according to a study led by scientists at Scripps Research and Howard Hughes Medical Institute (HHMI).
The discovery, published in the END ...
According to data from a cohort of adult and pediatric patients with antibody deficiencies, patients that often fail to make protective immune responses to infections and vaccinations showed robust T-cell activity and humoral immunity against SARS-CoV-2 structural proteins. The new study, led by researchers at Children's National Hospital, is the first to demonstrate a robust T-cell response against SARS-CoV-2 in immunocompromised patients.
"If T-cell responses to SARS-CoV-2 are indeed protective, then it could suggest that adoptive T-cell immunotherapy might benefit more profoundly immunocompromised patients," said Michael Keller, M.D., director of the Translational Research Laboratory in the ...
Scientists at the Skolkovo Institute of Science and Technology (Skoltech) and their colleagues from the University of Graz & the Kanzelhöhe Observatory (Austria) and the ESA European Space Operations Centre developed a method and software called RESONANCE to predict the solar radio flux activity for 1-24 months ahead. RESONANCE will serve to improve the specification of satellite orbits, re-entry services, modeling of space debris evolution, and collision avoidance maneuvers. The research results were published in the high-profile Astrophysical Journal Supplement Series.
Since the launch of Sputnik, the Earth's first artificial satellite, in ...
The work was sponsored by Russian Science Foundation; the project, headed by Professor Anatolii Mokshin, is titled "Theoretical, simulating and experimental research of physico-mechanical traits of amorphous-producing systems with heterogeneous local visco-elastic properties".
"We performed calculations for porous nitinol," shares first co-author, Associate Professor Bulat Galimzyanov. "It's widely used in various industries thanks to its unique physico-mechanical properties, such as low volume weight, high corrosion resistance, high biocompatibility and shape memory. Obtaining nitinol as amorphous foam is very labor-intensive, it requires high temperatures and extremely high melt cooling rate (over 1,000,000 K per second). Obviously, traditional experiments ...
A large-scale randomised trial of annual screening for ovarian cancer, led by UCL researchers, did not succeed in reducing deaths from the disease, despite one of the screening methods tested detecting cancers earlier.
Results from the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) have been published in a report in the medical journal The Lancet.
In the UK, 4,000 women die from ovarian cancer each year. It is not usually diagnosed until it is at a late stage and hard to treat. UKCTOCS was designed to test the hypothesis that a reliable screening ...
BOSTON - B cells are the immune cells responsible for creating antibodies, and most B cells, known as B2 cells, produce antibodies in response to a pathogen or a vaccine, providing defense and immunity against infections. But a small subset of long-lived B cells, known as B1 cells, are quite different from their short-lived cousins, the B2 cells. Instead of producing antibodies in response to invaders, they spontaneously make antibodies that perform vital housekeeping functions, such as removing waste like oxidized LDL cholesterol from the blood.
Like all the cells in the body, B1 and B2 cells have the same DNA, and therefore the same starting set of instructions. It is through epigenetic modifications, which ...
PROVIDENCE, R.I. [Brown University] -- Since the 1950s, political scientists have theorized that political polarization -- increased numbers of "political partisans" who view the world with an ideological bias -- is associated with an inability to tolerate uncertainty and a need to hold predictable beliefs about the world.
But little is known about the biological mechanisms through which such biased perceptions arise.
To investigate that question, scientists at Brown University measured and compared the brain activity of committed partisans (both liberals and conservatives) as ...
If you're a fan of spy movies, you've probably come across scenes where the intelligence agents try to identify or detect a perpetrator using some sophisticated image enhancement technology on surveillance camera images. While the idea behind surveillance cameras and object detection is the same in real life, unlike in movies, there is often a trade-off between the camera's field-of-view and its resolution.
Surveillance cameras are typically required to have a wide field-of-view to make the detection of a threat more likely. Due to this, omnidirectional ...
The first frost of autumn may be grim for gardeners but the latest evidence reveals it is a profound event in the life of plants.
The discovery may affect how we grow crops in a fluctuating climate and help us better understand molecular mechanisms in animals and humans.
Much of our understanding of how plants register temperature at a molecular level has been gained from the study of vernalization - the exposure to an extended period of cold as a preparation for flowering in spring.
Experiments using the model plant Arabidopsis have shown how this prolonged period of cold lifts the brake on flowering, a gene called FLC. This biochemical brake also involves another molecule COOLAIR which is antisense to FLC. This means it lies on the ...
