Category: Environmental Effects

Sunlight Might Cause New-onset Lupus

Photo by Julian Jagtenberg on Pexels

While a large, long-running epidemiologic study was unable to conclude that ultraviolet (UV) radiation in sunlight can cause new-onset systemic lupus erythematosus (SLE), trends in the data suggested that it could, according to findings reported in the journal Arthritis Care & Research.

Participants in the  who were in the upper tertile (third) of estimated UV-B exposure had 28% higher rates of incident SLE during follow-up.

Similar numerical increases in risk with high estimated UV-B exposure were seen for specific lupus subtypes and manifestations, such as SLE with photosensitivity or with anti-Ro/La antibodies, which also fell short of statistical significance, they reported

The study’s relatively small number of new-onset SLE cases – only 297 out of about six million person-years of data – was the likely reason for the broad confidence intervals. The study did also find one lupus subtype with a statistically significant association with UV-B exposure: SLE with malar rash (HR 1.62 for top versus bottom tertile, 95% CI 1.04-2.52).

“We found no overall association between high UV radiation exposure and risk of overall SLE in these large cohorts of women prospectively followed for many years prior to SLE onset,” the researchers acknowledged.

“However, cumulative average UV radiation exposure in the highest tertile was associated with non-significant but suggestive increased risk of the subtype of SLE presenting with cutaneous antibodies, including anti-Ro and/or anti-La antibodies, and/or cutaneous involvement, including malar rash (acute cutaneous lupus) and/or photosensitivity, which tend to co-occur, and are biologically plausible,” they stated.

Photosensitivity is a hallmark of lupus, and sunlight exposure is known to cause disease flareups in people with established SLE. Among the 297 cases of incident SLE that developed in NHS participants, 58% included photosensitivity. Other risk factors include smoking and exposure to silica. Exposure to strong sunlight might be another one, since UV radiation disrupts skin keratinocytes, releasing antigens that could trigger autoimmune attack.

The decades-long American Nurses’ Health Study (NHS) I and II has the medical records of 240 000 participants, mostly female, who completed detailed questionnaires.

However, new-onset SLE is rare enough that, even with that many participants, there weren’t enough cases to be sure whether risk increases in the 30%-50% range were real.

Other major limitations included having to estimate UV exposure from participants’ residence, race serving as an inexact proxy of skin tone, and no data on sunburn history or sunscreen use.

Source: MedPage Today

River Pollution from Pharmaceutical Production is Widespread

Pills and tablets
Photo by Myriam Zilles on Unsplash

Pharmaceutical ingredients from both prescription and over-the-counter drugs find their way into the environment during their production, use and disposal. They readily contaminate bodies of surface water such as rivers and lakes. Results from a recent study published in Environmental Toxicology and Chemistry indicate that pharmaceutical pollution is a problem that is affecting the world’s rivers. 

Approximately 43.5% of the 1052 locations that were assessed in the study across 104 countries had concerning concentrations of pharmaceutical ingredients. Twenty-three pharmaceutical ingredients occurred at concentrations that exceeded ‘safe’ concentrations, including substances from drug classes including antidepressants, antimicrobials, antihistamines, benzodiazepines, and painkillers.   

“This is the first truly global assessment of the impacts of single pharmaceuticals and mixtures of pharmaceuticals in riverine systems,” said corresponding author Alejandra Bouzas-Monroy, a PhD student at the University of York. “Our findings show that a very high proportion of rivers around the world are at threat from pharmaceutical pollution. We should therefore be doing much more to reduce the emissions of these substances into the environment.”  

Source: EurekAlert!

PFAS and Phthalates Linked to Reduced Bone Density in Teen Boys

Photo by Gayatri Malhotra on Unsplash

Per- and polyfluoroalkyl substances (PFAS) and phthalates (two types of endocrine-disrupting chemicals) may be associated with lower areal bone mineral density (aBMD) in teenage boys, according to a new study published in the Journal of Clinical Endocrinology and Metabolism.

Endocrine disrupting chemicals (EDCs) and potential EDCs are mostly man-made found in various materials. By interfering with the body’s endocrine system, endocrine disruptors produce adverse developmental, reproductive, neurological, and immune effects in humans, abnormal growth patterns and neurodevelopmental delays in children. These include per- and polyfluoroalkyl substances (PFAS) are used in non-stick pots and pans, clothing and food packaging, and are increasingly being found in US water supplies. Phthalates are used in medical devices, personal care products, food processing and children’s toys.

“Adolescence is an important time when our bodies build up bone. Almost all US children and adolescents are exposed to PFAS and phthalates, but few studies have looked at how these chemicals could be impacting our bone health,” said Abby F. Fleisch, MD, MPH, of the Maine Medical Center Research Institute and Maine Medical Center. “Our research found an association between certain PFAS and phthalates and reduced bone mineral density in adolescent males. Because bone accrual primarily occurs during adolescence, if replicated, this finding may have implications for lifelong bone health.”

The researchers accessed data on urine and blood samples from 453 boys and 395 girls from the National Health and Nutrition Examination Survey (NHANES). Participants were on average 15.1 years old, and found that higher levels of PFAS and phthalates may be associated with lower aBMD in adolescent males. The same effect was not found in girls; rather a slight increase in aBMD was observed for certain PFAS and phthalates.

The researchers noted that bone mineral density tracks across a lifetime, so if the same results are seen in longitudinal cohorts, this finding may have implications for lifelong skeletal health.

Source: The Endocrine Society

New Evidence-based Recommendations for Light Exposure

Sleeping woman
Photo by Cottonbro on Pexels

For the first time, a set of recommendations have been drawn up to provide guidance for human exposure to light throughout the day and at nighttime, based on the amount of blue light in the environment. The recommendations are detailed in PLOS Biology.

Modern lifestyles, with 24-hour access to electric light and reduced exposure to natural daylight, can disrupt sleep and negatively impact health, well-being, and productivity. A new report in PLOS Biology addresses the issue of exactly how bright lighting should be during the day and in the evening to support healthy body rhythms, restful sleep, and daytime alertness.

An international body of leading scientific experts was brought together to draw up the first evidence-based, consensus recommendations for healthy daytime, evening, and nighttime light exposure. These recommendations provide much needed guidance to the lighting and electronics industries to aid the design of healthier environments and to improve how we light our workplaces, public buildings, and homes.

The new report took on a key question – how to properly measure the extent to which different types of lighting might influence circadian rhythms and sleep patterns. Light affects these patterns via a specialised type of cell in the eye that uses a light sensitive protein, melanopsin, that is distinct from the opsin in the rods and cones that support vision (and upon which traditional ways of measuring “brightness” are based). Since melanopsin is most sensitive to blue-cyan light, the new recommendations used a newly-developed light measurement standard tailored to this unique property: melanopic equivalent daylight illuminance. Analysis of data from a variety of studies proved that this new measurement approach could provide a reliable way of predicting the effects of light on human physiology and body rhythms, and so could form the basis of widely applicable and meaningful recommendations.

A crucial next step will be to integrate the recommendations into formal lighting guidelines, which currently focus on visual requirements rather than effects on health and well-being. Additionally, advances in LED lighting technology and the availability of low-cost light sensors are expected to increase the ease with which individuals can optimise their personal light exposure to best support their own circadian rhythms in line with the new recommendations.

Professor Timothy Brown, who brought the international exports together for the report added: “These recommendations provide the first scientific consensus, quantitative, guidance for appropriate daily patterns of light exposure to support healthy body rhythms, nighttime sleep and daytime alertness. This now provides a clear framework to inform how we light any interior space ranging from workplaces, educational establishments and healthcare facilities to our own homes.”

Source: Science Daily

Lead Exposure Lowered IQ of Americans Born Up to 1996

Old petrol pump
Photo by Ashlee Attebery on Unsplash

A new study calculates that exposure to car exhaust from leaded gas during childhood lowered the IQ levels of about half the population of Americans alive today.

The findings suggest that Americans born before 1996 may now be at greater risk for lead-related health problems, such as faster ageing of the brain. Leaded petrol was banned in the US in 1996, but anyone born in the US before the end of that era, and especially those at the peak of its use in the 1960s and 1970s, had worryingly high lead exposures as children, the researchers said. In South Africa, leaded petrol was only banned at the end of 2005.

The study’s findings were published in Proceedings of the National Academy of Sciences.

Lead is a neurotoxin that can enter the bloodstream via a number of routes and there is no safe level of exposure at any point in life. Young children are especially vulnerable to lead’s ability to impair brain development and lower cognitive ability.

“Lead is able to reach the bloodstream once it’s inhaled as dust, or ingested, or consumed in water,” said study co-author Aaron Reuben, a PhD candidate in clinical psychology. “In the bloodstream, it’s able to pass into the brain through the blood-brain barrier, which is quite good at keeping a lot of toxicants and pathogens out of the brain, but not all of them.”

To answer the complex question of how more than 70 years of leaded petrol use may have left a permanent mark on human health, Reuben and co-authors Michael McFarland and Mathew Hauer, both professors of sociology at Florida State University, opted for a fairly simple strategy.

Using publicly available data on US childhood blood-lead levels, leaded-gas use, and population statistics, they determined the likely lifelong burden of lead exposure carried by every American alive in 2015. From this data, they estimated lead’s assault on our intelligence by calculating IQ points lost from leaded gas exposure as a proxy for its harmful impact on public health – a result which stunned the researchers.

“I frankly was shocked,” Prof McFarland said. “And when I look at the numbers, I’m still shocked even though I’m prepared for it.”

As of 2015, more than 170 million Americans (more than half of the U.S. population) had clinically concerning levels of lead in their blood as children, likely resulting in lower IQs and putting them at higher risk for other long-term health impairments, such as reduced brain size, greater likelihood of mental illness, and increased cardiovascular disease in adulthood.

Leaded gasoline consumption rose rapidly in the early 1960s and peaked in the 1970s. As a result, Reuben and his colleagues found that essentially everyone born during those two decades are all but guaranteed to have been exposed to pernicious levels of lead from car exhaust.

Even more startling was lead’s toll on intelligence: childhood lead exposure may have blunted America’s cumulative IQ score by an estimated 824 million points – nearly three points per person on average. The researchers calculated that at its worst, people born in the mid-to-late 1960s may have lost up to six IQ points, and children registering the highest levels of lead in their blood, eight times the current minimum level to initiate clinical concern, fared even worse, potentially losing more than seven IQ points on average.

While the loss of a few IQ points may seem negligible, the authors note that these changes are dramatic enough to potentially shift people with below-average cognitive ability (IQ score less than 85) to being classified as having an intellectual disability (IQ score below 70).

Prof McFarland is continuing by analysing the racial disparities of childhood lead exposure, hoping to highlight the health inequities suffered by Black children, who were exposed more often to lead and in greater quantities than white children.

Reuben’s next step will be to examine the long-term consequences of past lead exposure on brain health in old age, based on evidence showing that adults with high childhood lead exposure may experience accelerated brain aging.

“Millions of us are walking around with a history of lead exposure,” Reuben said. “It’s not like you got into a car accident and had a rotator cuff tear that heals and then you’re fine. It appears to be an insult carried in the body in different ways that we’re still trying to understand but that can have implications for life.”

Source: Duke University

Climate Change Will Increase Deaths Linked to Extreme Temperatures

Heat cracked earth
Photo by Joshua Woroniecki on Unsplash

The death rate linked to extreme temperatures will increase significantly under global warming of 2°C, with even steeper rises for each degree of warming, finds a report published in Environmental Research Letters.

With a warming scenario of just 2°C from pre-industrial levels, temperature-related mortality in England and Wales during the hottest days of the year will increase by 42%. This means an increase from present-day levels of around 117 deaths per day, averaged over the 10 hottest days of the year, to around 166 deaths per day. The findings underline the importance of keeping global warming levels to below 2°C.

At current global warming levels of around 1.21°C there would be a slight decrease in temperature-related mortality in winter and a minimal net effect in summer, meaning that overall, at this level of warming we see a slight decrease in temperature-related mortality rate.

The researchers assessed the impact of climate change on mortality rates England and Wales, specifically risk from heat in summer and cold in winter. They found that as the global mean temperature increases, temperature-related mortality in summer will increase at a much faster, non-linear rate.

The rate of increase particularly speeds up at 2°C of warming, with a much higher risk appearing beyond 2.5°C. The researchers say that 3°C warming could lead to a 75% increase in mortality risk during heatwaves.

The relationship between temperature and mortality on a graph is roughly U-shaped, meaning that at extremely high temperatures, mortality risk increases sharply for each degree rise of daily mean temperature.

The rate in winter will continue to decrease, although this leaves out extreme weather events such as storms.

Lead author Dr Katty Huang said: “The increase in mortality risk under current warming levels is mainly notable during heatwaves, but with further warming, we would see risk rise on average summer days in addition to escalating risks during heatwaves. What this means is that we shouldn’t expect past trends of impact per degree of warming to apply in the future. One degree of global warming beyond 2°C would have a much more severe impact on health in England and Wales than one degree warming from pre-industrial levels, with implications for how the NHS can cope.”

In England and Wales, temperature is associated with around 9% of total population mortality, meaning that 9% of all deaths during 2021 could be associated with the temperature. Most of those deaths are related to the side effects of cold weather.

The team analysed the 2018 UK Climate Projections (UKCP18) with data on present-day temperature and mortality in order to predict changes in temperature-related mortality relative to degrees of global warming.

In order to isolate the effects of global warming on mortality risk, the researchers looked at the potential impact for the current population, and not attempting to predict future age distributions and medical conditions.

Project lead Professor Andrew Charlton-Perez said: “As the Intergovernmental Panel on Climate Change impacts report recently showed, it is increasingly common to examine how different levels of mean global warming raise the risk of significant harm to people and society. Our study shows that because death rates will go up significantly if countries experience very high temperatures, limiting the average global rise in temperatures is likely to have substantial benefits for the overall health of the population.”

Source: University College London

Ozone Linked to Cognitive Impairment with Age

Photo by Kouji Tsuru on Unsplash

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.

Source: Yale University

Lab Results are Influenced by Ambient Daily Temperatures

Photo by Louis Reed on Unsplash

Ambient temperature influences many common lab tests, and these distortions likely affect medical decision making, such as whether to prescribe medications, according to new research published in the journal Med

To account for this, the researchers suggest that laboratories could statistically adjust for ambient temperature on test days when reporting lab results.

“When a doctor orders a laboratory test, she uses it to shed light on what’s going on inside your body, but we wondered if the results of those tests could also reflect something that’s going on outside of your body” said study co-author Ziad Obermeyer of the University of California, Berkeley. “This is exactly the kind of pattern that doctors might miss. We’re not looking for it, and lab tests are noisy.”

Delving into this problem, Obermeyer and Devin Pope of the University of Chicago analysed a large dataset of test results from different climates. In a sample of more than four million patients, they modelled more than two million test results based on temperature. They measured how day-to-day temperature fluctuations influenced results, over and above the patients’ average values, and seasonal variation.

Temperature was found to affect more than 90% of individual tests and 51 of 75 assays, including measures of kidney function, cellular blood components, and lipids such as cholesterol and triglycerides. “It’s important to note that these changes were small: less than one percent differences in most tests under normal temperature conditions,” Obermeyer said.

These small fluctuations did not likely reflect long-term physiological trends. For example, lipid panels checked on cooler days appeared to suggest a lower cardiovascular risk, resulting in almost 10% fewer prescriptions for cholesterol-lowering drugs called statins to patients tested on the coolest days compared to the warmest days, despite the results likely not reflecting stable changes in cardiovascular risk.

Since the study wasn’t an experiment, the exact mechanisms underlying the fluctuations in lab results could not be pinpointed. However, blood volume, specific assay performance, specimen transport, or changes in lab equipment might explain them. “Whatever their cause, temperature produces undesirable variability in at least some tests, which in turn leads to distortions in important medical decisions,” Pope said.

Laboratories could get around this by statistically adjusting for ambient temperature on the test day when reporting lab results. This could be a way to reduce weather-related variability without expensive temperature control equipment. 

In practice, decisions on adjustment would need to be at the discretion of the laboratory staff and the treating physician, potentially on a case-by-case basis.

According to the authors, the study may also have broader clinical implications. “The textbook way of thinking about medical research is bench to bedside. First, we come up with a hypothesis, based on theory, then we test it with data,” Obermeyer said. “As more and more big data comes online, like the massive dataset of lab tests we used, we can flip that process on its head: discover fascinating new patterns and then use bench science to get to the bottom of it. I think this bedside-to-bench model is just as important as its better-known cousin because it can open up totally new questions in human physiology.”

Source: Science Daily

Extreme Heat Health Risks Are Higher for Younger Adults

Photo by Ketut Subiyanto on Pexels

A new study in the US has found that complications from extreme heat appear to be more pronounced among young and middle-aged adults than older adults.

Extreme heat poses an increasing threat to the public, due to the continued effects of climate change. Although the adverse health impacts of heat have been well documented among older adults, less is known about the potential impacts of heat on young and middle-aged adults.

Published in the BMJ, the study examined the relationship between extreme temperatures and emergency department (ED) visits, and found that days of extreme heat were associated with an increase risk of ED visits for any cause, heat-related illness, renal disease, and mental disorders among all adults, but the strongest association was found among adults ages 18-64.

Prior research on heat’s health impacts have mostly focused on mortality or hospital admissions among seniors. This study is the first national-scale assessment of extreme heat effects on adults of all ages, measured with ED visits.

“Many illnesses that lead to utilisation of the ED do not lead to hospitalisation because they can be treated in a short amount of time, particularly among the younger adult population,” said study senior author Gregory Wellenius, professor of environmental health and director of the Program on Climate and Health at SPH. “By looking at emergency room visits, we aimed to obtain a more comprehensive picture of the true burden of disease that might be attributed to the days of high heat.”

Prof Wellenius and colleagues analysed healthcare claims data to quantify the risk of ED visits for any cause and for heat-associated conditions during the warm season (between May and September) from 2010 to 2019.

For the study, the researchers analysed claims data among 74 million adults, including more than 22 million ED visits. They found that days of extreme heat (varying by location, but averaging about 34°C), were associated with a 66% greater risk of ED visits for heat-related illness, as well as a 30% increased risk for renal disease, compared to ED visits on cooler days. But the risk according to extreme heat varied by age. A day of extreme heat was associated with a 10.3% higher risk of ED visits among people ages 45 to 54 years old, compared to a 3.6% higher risk among those older than 75.

“Younger adults may be at greater risk of exposure to extreme heat, particularly among workers that spend substantial time outdoors,” says study lead author Shengzhi Sun, research scientist in the Department of Environmental Health at SPH. “Younger adults may also not realise that they too can be at risk on days of extreme heat.”

Prior studies had shown that people in US counties with lower warm-season temperatures still experience higher risks of heat-related complications.
“While extreme heat threatens everyone’s health, this study provides further evidence that it is especially dangerous in regions with cooler climates that may be less adapted to heat,” says study co-author Kate Weinberger, assistant professor at the University of British Columbia’s School of Population and Public Health. “As temperatures continue to rise due to climate change, the implementation of heat adaptation measures in these regions will be critically important.”

According to the researchers, many of these heat-related complications can be prevented through policy changes that reduce exposure to heat, or improve people’s susceptibility and adaptivity to heat.

“By looking at emergency department visits for different causes and for several age groups, we were able to characterise with accuracy the varying impact on health on different populations,” said study co-author, Professor Francesca Dominici. “An important goal of this study is to provide actionable information to clinicians and public health experts regarding how to prevent these emergency department visits, also considering that we can anticipate when these extreme heat events are likely to occur.”

Source: Boston University

Extreme Heat Threatens Cardiovascular Health

Photo from Olivier Collett on Unsplash
Photo from Olivier Collett on Unsplash


With South Africa’s summer being expected to be both wetter and hotter this year, there is a greater risk of adverse cardiovascular incidents, especially for adults with pre-existing cardiovascular diseases. Experts writing in the Canadian Journal of Cardiology discuss how extreme heat affects cardiovascular health, why health professionals should care and what recommendations they can make to minimise consequences.

Extreme heat events are predicted to become longer, more common and more severe. Some 70 000 heat-related deaths occurred during the 2003 European heatwave. Risk factors for heat-related hospitalisation include age, chronic illnesses, social isolation, some medications, and lack of access to air conditioning. Among chronic illnesses, cardiovascular diseases are often identified as a risk factor for heat-related hospitalisation and death.

The Intergovernmental Panel on Climate Change (IPCC) recently reported that global temperatures are rising at a greater rate than previously projected, and that the number of extreme heat days will significantly increase across most land regions,” said senior author Daniel Gagnon, PhD, University of Montreal. “Although we don’t yet fully understand the reasons, people with cardiovascular disease are at greater risk of hospitalisations and death during extreme heat events.”

The researchers reviewed studies and noted a consistent association between extreme heat and increased risk of adverse cardiovascular outcomes. An examination of reviews and meta-analyses on the effect of extreme heat on adverse cardiovascular outcomes showed that heatwaves significantly increase mortality risk from ischaemic heart disease, stroke, and heart failure.

“Although the effects of extreme heat on adverse cardiovascular events have been explained in the context of heatstroke, many events occur without heatstroke, and the mechanisms of these events in the absence of heatstroke remain unclear,” observed Dr Gagnon. “It is likely that heat exposure increases myocardial oxygen needs.”

One possibility is that heat exposure puts excessive strain on the heart for individuals with heart disease and that heat exposure increases the risk of blood clots forming within cardiac blood vessels.

The authors propose that preventive strategies should aim to reduce the extent of hyperthermia and dehydration. In Canada, heat-health warnings systems act as a first line of defence by raising awareness of upcoming heat events and recommending strategies to minimise possible heat complications. For example, heat warnings are issued 18-24 hours before a heat event in Ontario and Québec, when ambient temperature will remain above 30°C for a minimum of two days. Public advisories include identifying the signs of heat stress, ensuring people drink adequate amounts of cold fluid or seeking an air-conditioned environment – though for many people, this is not an option.

Recent research supports electric fan use, skin wetting and immersing the feet in tap water as simple methods to stay cool during extreme heat events. “Air conditioning is the most effective strategy that can be recommended since it effectively removes the heat stimulus and minimises the risk of adverse cardiovascular outcomes,” commented Dr Gagnon. “However, less than one third of global households own air conditioning.”

More studies are needed to explain why extreme heat is linked to increased risk of adverse cardiovascular outcomes; the effect of cardiovascular medication on the human body’s physiological responses during heat exposure; the best cooling strategies in heat waves for individuals with CVD; and safe environmental limits for outdoor exercise in individuals with heart disease.

“Cardiovascular health professionals need to be aware of the negative consequences of extreme heat on cardiovascular health. A better awareness and understanding of the cardiovascular consequences of extreme heat, and of the measures to take to prevent and mitigate adverse events, will help us all assess the risk and optimize the care of patients exposed to an increasingly warm climate,” concluded Dr Gagnon.

Source: Elsevier