New research published in Arthritis & Rheumatologyindicates that chronic exposure to air pollutants may increase the risk of developing lupus, an autoimmune disease that affects multiple organs.
For the study, investigators analysed data on 459 815 participants from the UK Biobank. A total of 399 lupus cases were identified during a median follow-up of 11.77 years. Air pollutant exposure was linked with a greater likelihood of developing lupus. Individuals with a high genetic risk and high air pollution exposure had the highest risk of developing lupus compared with those with low genetic risk and low air pollution exposure.
“Our study provides crucial insights into the air pollution contributing to autoimmune diseases. The findings can inform the development of stricter air quality regulations to mitigate exposure to harmful pollutants, thereby reducing the risk of lupus,” said co–corresponding author Yaohua Tian, PhD, of the Huazhong University of Science and Technology, in China.
Those pot plants in GPs’ waiting room may have an additional health benefit in addition to sprucing the place up. A ground-breaking study has revealed that plants can efficiently remove toxic gasoline fumes, including cancer causing compounds such as benzene, from indoor air.
The study was led by University of Technology Sydney (UTS) bioremediation researcher Associate Professor Fraser Torpy, in partnership with leading Australian plantscaping solutions company Ambius.
The researchers found that the Ambius small green wall, containing a mix of indoor plants, was highly effective at removing harmful, cancer-causing pollutants, with 97 per cent of the most toxic compounds removed from the surrounding air in just eight hours.
Poor indoor air quality is responsible for 6.7 million premature deaths globally, according to the World Health Organisation. Most people spend 90% of their time indoors at home, school or the workplace, so adopting new strategies to improve air quality is critical.
Ambius General Manager Johan Hodgson said the research presented new evidence into the critical role played by indoor plants and green walls in cleaning the air we breathe quickly and sustainably.
“We know that indoor air quality is often significantly more polluted than outdoor air, which in turn impacts mental and physical health. But the great news is this study has shown that something as simple as having plants indoors can make a huge difference,” Mr Hodgson said.
Previous studies on indoor plants have shown they can remove a broad range of indoor air contaminants, however this is the first study into the ability of plants to clean up gasoline vapors, which are one of the largest sources of toxic compounds in buildings worldwide.
Offices and residential apartment buildings often connect directly to parking garages, either by doors or elevator shafts, making it difficult to avoid harmful gasoline-related compounds seeping into work and residential areas. Many buildings are also exposed to gasoline fumes from nearby roads and highways.
Breathing gasoline fumes can lead to lung irritation, headaches and nausea, and has been linked to an increased risk of cancer, asthma and other chronic diseases from longer term exposure, contributing to decreased life expectancy.
Associate Professor Torpy said the study results, based on measurements from a sealed chamber, had far exceeded their expectations when it came to removing gasoline pollutants from the air.
“This is the first time plants have been tested for their ability to remove gasoline-related compounds, and the results are astounding.
“Not only can plants remove the majority of pollutants from the air in a matter of hours, they remove the most harmful gasoline-related pollutants from the air most efficiently, for example, known carcinogen benzene is digested at a faster rate than less harmful substances, like alcohols.
“We also found that the more concentrated the toxins in the air, the faster and more effective the plants became at removing the toxins, showing that plants adapt to the conditions they’re growing in,” Associate Professor Torpy said.
Mr Hodgson said the findings confirmed feedback they’d received after installing plants in hundreds of office buildings across the nation.
“At Ambius, we see over and over again the effects plants have in improving health, wellbeing, productivity and office attendance for the thousands of businesses we work with. This new research proves that plants should not just be seen as ‘nice to have’, but rather a crucial part of every workplace wellness plan.
“The bottom line is that the best, most cost effective and most sustainable way to combat harmful indoor air contaminants in your workplace and home is to introduce plants,” Mr Hodgson said.
Exposure to polycyclic aromatic hydrocarbons (PAH), formed from burning various substances such as coal, wood or tobacco, or from grilled meat, is strongly linked to a person’s risk of developing rheumatoid arthritis, suggests research published in the open access journal BMJ Open.
These chemicals also seem to account for most of smoking’s impact on risk of the disease, the findings indicate. Growing evidence links several environmental toxicants with various long term conditions. But few studies have looked at their association with inflammatory conditions, such as rheumatoid arthritis, which is thought to arise from an interplay between genes, sex, and age, and environmental factors, including smoking, nutrition, and lifestyle.
To try and shed some light on the potential role of environmental exposure on rheumatoid arthritis risk, the researchers drew on responses to the nationally representative US National Health and Nutrition Examination Survey (NHANES) between 2007 and 2016.
NHANES evaluates a wide variety of toxicants, including PAH; chemicals used in the manufacture of plastics and various consumer products (PHTHTEs); and volatile organic compounds (VOCs), derived from paints, cleaning agents, and pesticides, among other things; along with data related to health, nutrition, behaviours and the environment.
The study included 21 987 adults, 1418 of whom had rheumatoid arthritis and 20 569 of whom didn’t. Blood and urine samples were taken to measure the total amount of PAH (7090 participants), PHTHTEs (7024), and VOCs (7129) in the body.
The odds of rheumatoid arthritis were highest among those in the top 25% of bodily PAH levels, irrespective of whether or not they were former or current smokers.
After accounting for potentially influential factors, including dietary fibre intake, physical activity, smoking, household income, educational attainment, age, sex, and weight (BMI), only one PAH, 1-hydroxynaphthalene, was strongly associated with higher odds (80%) of the disease.
PHTHTE and VOC metabolites weren’t associated with heightened risk after accounting for potentially influential factors.
Somewhat surprisingly, however, smoking wasn’t associated with heightened rheumatoid arthritis risk either, after accounting for PAH levels in the body.
And further analysis to separate out the influences of PAH and smoking showed that bodily PAH level accounted for 90% of the total effect of smoking on rheumatoid arthritis risk.
This is an observational study, and as such, can’t determine cause. And the researchers acknowledge various limitations to their findings, including that measurements of environmental toxicants in fat (adipose) tissue weren’t available.
Nor did they measure heavy metal levels which have previously been linked to rheumatoid arthritis risk. Cigarettes are a major source of the heavy metal cadmium.
But they write: “To our knowledge, this is the first study to demonstrate that PAH not only underlie the majority of the relationship between smoking and [rheumatoid arthritis], but also independently contribute to [it].
“This is important as PAH are ubiquitous in the environment, derived from various sources, and are mechanistically linked by the aryl hydrocarbon receptor to the underlying pathophysiology of [rheumatoid arthritis].”
They add: “While PAH levels tend to be higher in adults who smoke…other sources of PAH exposure include indoor environments, motor vehicle exhaust, natural gas, smoke from wood or coal burning fires, fumes from asphalt roads, and consuming grilled or charred foods.
“This is pertinent as households of lower socioeconomic status generally experience poorer indoor air quality and may reside in urban areas next to major roadways or in high traffic areas.” These people may therefore be particularly vulnerable, they suggest.
A robust link has been established between long-term ozone exposure and an increased risk of cognitive impairment in older adults, according to a large-scale study published in Environment International.
Air pollution has long been considered a major risk factor for an ageing society. Fine airborne particulate matter can lead to dementia and other cognitive disabilities. But beyond airborne particles, little is known about the way in which other pollutants can pose a similar danger.
The researchers chose to focus on ambient ozone, a highly reactive gas that exists in much of smog at ground level. They then observed health outcomes in nearly 10 000 older adults across China and analysed the extent to which long-term ozone exposure may have impacted their cognitive ability over time.
The results, they found, were startling. For every 10 microgram increase of yearly average ozone exposure, the risk for cognitive impairment grew by more than 10%. Through their analysis, the researchers also found that this association held even when they abstracted away individual risk factors such as smoking, drinking and education level. That is, older adults in China who were exposed to high levels of yearly ozone pollution were more likely to develop cognitive disabilities later in life, no matter what other activities they were involved in.
“Our findings suggest potential benefits in delaying the progression of cognitive decline among older adults if ozone levels are reduced below the new WHO Global Air Quality Guideline for ozone pollution,” said Kai Chen, Ph.D., assistant professor at the Yale School of Public Health and the study’s lead author.
The researchers acknowledged limitations such as observational data being unable to establish a causal link. More research is needed into ozone’s destructive mechanism. And since many older adults in China spend more time indoors, their ozone exposure may be different.
Nonetheless, the findings match what other researchers have found in areas across the globe: Over the past several years, studies have traced a similar link in adults in the United States and in Taiwan, and have also found an association between ozone exposure and other neurological diseases.
The study shows that ozone exposure needs to be curbed worldwide to prevent healthcare systems from being overwhelmed as populations age and pollution increases.
Study co-author Professor Robert Dubrow said what makes this issue more urgent is that “ozone pollution is projected to be worsening under climate change.” Reducing this threat could bring significant benefits to public health and improve quality of life.
Chronic exposure to air pollution in the form of particulate matter contributes to the risk of cardiovascular and respiratory diseases, and in particular has been linked to hypertension, according to a study published in Scientific Reports.
Air pollution, accounting for more than 4.2 million deaths annually, is a significant health risk. The study assessed the impact of particulate pollution on the long-term incidence of hypertension in Spain, supporting the need to improve air quality to the extent possible in order to reduce the risk of cardiometabolic diseases among the population.
To this end, researchers have carried out a study, di@bet.es, which recruited 1103 participants aged 18–83. None of the participants presented with hypertension at the start of the study (2008–2010), and they were monitored until 2016–17. Participants were assigned air pollution concentrations for particulate matter, obtained through modeling and air quality readings. During this period, 282 cases of incident hypertension were recorded.
The study was carried out in collaboration with the air pollution department of the Research Centre for Energy, Environment and Technology (CIEMAT).
As explained by endocrinologist Sergio Valdés, “Several previous studies have described the short- and long-term association of ambient air pollutants with hypertension and blood pressure levels, but few studies have addressed the association between long-term exposure to these particles and the incidence of hypertension in a prospective manner. Therefore, the di@bet.es study has offered us the opportunity to do so in the Spanish population.”
Participants underwent a medical examination and had blood samples taken. They also answered questionnaires to obtain demographic information and variables such as smoking, exercise and diet.
Gemma Rojo, last study author, stated that “our data is consistent with a large body of evidence suggesting that air pollution may contribute to the pathogenesis of hypertension. It also supports the idea that the particulate component of air pollution is the greatest threat to the cardiovascular system.”
In this regard, she noted, “Although previous associations between exposure to gaseous pollutants and hypertension have shown some discrepancies, most studies reporting long-term exposure to particulate matter and incident high blood pressure have reported positive associations consistent with our findings.”
As Sergio Valdés explained, “our results support the need to improve air quality to the extent possible in order to reduce the risk of high blood pressure among our population, as even moderate levels such as those we report here increase the risk significantly.”
New WHO Global Air Quality Guidelines (AQGs) have lowered the acceptable limits of air pollution, providing evidence that even lower concentrations than previously understood have a negative health impact.
Increasing evidence showing how air pollution affects different aspects of health, WHO has adjusted almost all the AQGs levels downwards, warning that exceeding the new air quality guideline levels is associated with significant risks to health.
Air pollution is estimated to cause 7 million premature deaths and the loss of millions more healthy years of life. In children, this could include reduced lung growth and function, respiratory infections and aggravated asthma. In adults, deaths from ischaemic heart disease and stroke are the most common, as well as emerging evidence of diabetes and neurodegenerative conditions. This makes the disease burden from air pollution on par with others such as unhealthy diet and tobacco smoking.
Besides climate change, air pollution is one of the biggest environmental threats to human health. Improving air quality will also help mitigate climate change, thereby reducing the negative health impacts of both. WHO’s new guidelines recommend air quality levels for 6 pollutants, where evidence has advanced the most on health effects from exposure. When action is taken on these so-called classical pollutants – particulate matter (PM), ozone (O₃), nitrogen dioxide (NO₂) sulfur dioxide (SO₂) and carbon monoxide (CO), it also has an impact on other damaging pollutants.
Particulate matterequal or smaller than 10 and 2.5 microns (µm) in diameter (PM₁₀ and PM₂.₅, respectively) is a particular health concern. Both PM₂.₅ and PM₁₀ can penetrate deep into the lungs but PM₂.₅ can even enter the bloodstream, primarily resulting in cardiovascular and respiratory impacts, and also affecting other organs, and were classified as carcinogenic in 2013.
“Air pollution is a threat to health in all countries, but it hits people in low- and middle-income countries the hardest,” said WHO Director-General, Dr Tedros Adhanom Ghebreyesus. “WHO’s new Air Quality Guidelines are an evidence-based and practical tool for improving the quality of the air on which all life depends. I urge all countries and all those fighting to protect our environment to put them to use to reduce suffering and save lives.”
In 2019, over 90% of the world’s population lived in areas where concentrations exceeded the 2005 WHO air quality guideline for long term exposure to PM₂.₅.
Almost 80% of PM₂.₅-related deaths could be avoided if current air pollution levels were reduced to those proposed in the updated guideline. At the same time, reaching interim targets would reduce the burden of disease, of which the greatest benefit would be observed in countries with high concentrations of fine particulates (PM₂.₅) and large populations.
Long-term exposure to air pollution appears to still be linked to higher mortality despite the existence of air quality standards that restrict levels of pollution, suggests a study published online in The BMJ today.
Previous studies have found an association between long term exposure to outdoor air pollution such as those in the form of fine particles in the air (known as particulate matter or PM2.5) and nitrogen dioxide (NO2) and illness or mortality.
While air pollution concentrations have fallen substantially in Europe since the 1990s, it is unclear whether there still is a link between pollution and ill health or death at pollution levels under permitted levels.
Therefore, researchers set out to determine if there was an association between low levels of air pollution concentrations and natural and cause-specific deaths.
Low-level air pollution was defined as concentrations below current limits set by the European Union, US Environmental Protection Agency and the World Health Organization (WHO).
The researchers analysed data on eight groups of people within six European countries. Their study recruited participants in the 1990s or 2000s. Of the 325 367 participants who were followed up over an almost 20-year period, around 14.5% (47 131 people) died during the study period.
An increase of 5 µg/m3 (a concentration measure of particulate matter) in particulate matter (PM2.5) was associated with a 13% increase in natural deaths while the corresponding figure for a 10 µg/m3 increase in nitrogen dioxide was 8.6%. Associations with PM2.5 and NO2 were largely independent of each other.
Moreover, even at low to very low concentrations, associations with PM2.5, NO2, and black carbon remained significant. For people exposed to pollution levels below the US standard of 12 µg/m3, an increase of 5 µg/m3 in PM2.5 was associated with a 29.6% increase in natural deaths. People exposed to NO2at less than half the current EU standard of 40 µg/m3, a 10 µg/m3 increase in NO2 was associated with a 9.9% increase in natural deaths.
The study also has some limitations, the researchers said, such as the fact that it focused on exposure in 2010 which was towards the end of the follow-up period for most participants and, given falling air pollution, this measure might not exactly reflect the concentrations experienced during follow-up.
However, this was a large study from multiple European groups of people with detailed information provided. As such, the authors concluded: “Our study contributes to the evidence that outdoor air pollution is associated with mortality even at levels below the current European and North American standards and WHO guideline values.
“These findings are therefore an important contribution to the debate about revision of air quality limits, guidelines and standards, and future assessments by the Global Burden of Disease [study].”
