Wednesday, March 01, 2023

How does wildfire smoke affect pregnancy and children?

UC Davis Health researchers awarded $1.35 million EPA grant to study impact of wildfire smoke on pregnancy, health and development

Grant and Award Announcement

UNIVERSITY OF CALIFORNIA - DAVIS HEALTH

How does exposure to wildfire smoke affect pregnant people and their developing babies? UC Davis Health researchers hope to answer that question, thanks to a new two-year, $1.35 million grant from the Environmental Protection Agency.

The study is led by molecular epidemiologist Rebecca J. Schmidt, an associate professor in Public Health Sciences, and Miriam Nuño, a professor in the Division of Biostatistics.

The researchers are gathering birth and health records as well as data about wildfire smoke exposure in California. They’ll look for links between pollution from wildfire smoke and low birth weight, developmental delays and autism.

The team is also partnering with regional organizations to educate underserved communities about the impact of smoke and provide strategies to reduce exposure.

“This is a California study, but the whole country is being exposed to wildfire smoke,” explained Schmidt, who is also a faculty member at the UC Davis MIND Institute, the Perinatal Origins of Disparities (POD) Center, and the Environmental Health Sciences Center. “It’s important to find out what the real concerns during pregnancy may be — including perhaps at what times during pregnancy we need to have moms be the most careful about their exposure.”

Schmidt has a history of studying the impacts of wildfire smoke on pregnancy and children. Her previous research involved collecting hair, blood and other samples from pregnant people and newborns. Her findings from that study will complement this new work.

Collecting data on smoke exposure, births and health

Wildfire seasons are becoming longer and more severe. It is estimated that wildfire smoke is linked to 339,000 premature deaths each year worldwide.

In California, where massive wildfires such as the Camp, Caldor and Dixie fires have affected both urban and rural areas, hundreds of thousands of pregnant people have been exposed to wildfire smoke.

“Studies have shown associations between wildfire smoke and lower birth weight or preterm birth, which are linked to later health outcomes,” Schmidt said.

The study has four areas of focus:

Find out which areas of California were exposed to the most wildfire air pollution.
Study wildfire smoke exposures before pregnancy and during each trimester of pregnancy. Researchers will look at these in relation to birth weight and gestational age as well as factors like neighborhood and local environment.
Explore associations between wildfire smoke exposure and autism and developmental delays.
Work with community partners to share research results and tools to help reduce smoke exposure in vulnerable populations.

“Our first step is to see who has the greatest exposures to these repeated wildfire events,” Schmidt explained. “Then we’ll look at how that varies by factors such as race, ethnicity, rural versus urban location, poverty level and exposure to other pollutants.”

The study will include all people born in California between Jan. 1, 2000, and Dec. 31, 2021 — roughly 11 million births. However, when looking at autism and developmental delays, researchers will only include people over 3 years of age by the end of 2021. Autism diagnosis is typically more reliable after this age.

Researchers will use state birth records, historical air monitor readings and health records from the California Department of Developmental Services.

Empowering vulnerable populations

The study aims to identify vulnerable populations where people are exposed not only to wildfire smoke but also to other pollution and pesticides and have less access to health care.

“Even though we are all exposed to wildfire smoke, we all have different risks,” explained Nuño. “If you have can work from home versus having an outdoor job, this is where these differences really manifest.”

The researchers are partnering with the March of Dimes, Empower Yolo and the Knights Landing One Health Center, which provides health care in the rural Central Valley community.

Together, they’ll deliver their findings and strategies for reducing exposure to wildfire smoke to underserved communities. This will include providing the materials and training to help people make Corsi-Rosenthal Air Boxes. This is a low-cost filtration system that’s been shown to be effective at removing particulates from indoor air. Creator Richard L. Corsi, dean of the UC Davis College of Engineering, is a partner on the project.

“This project will advance solutions to challenges lying at the intersection of climate change and environmental justice, both here in California and in communities around the country,” said EPA Pacific Southwest Regional Administrator Martha Guzman. “Advancing scientific research that helps protect public health and the environment is central to EPA’s mission and this project will have lasting results for years to come.”

Environmental justice is a major focus, notes Nuño, who is also the interim director of the Center for Healthcare Policy and Research.

“Pregnant women are stressed about the impact of wildfires — especially those who are more vulnerable. Justice calls for empowering these women with this information,” she said.

Other collaborators include:

Beate Ritz, professor of epidemiology, environmental health and neurology at UCLA
Irva Hertz-Picciotto, director of the Environmental Health Sciences Center
Kathryn Conlon, assistant professor in the Department of Public Health Sciences and School of Veterinary Medicine, Department of Medicine and Epidemiology
Michael Kleeman, professor, Department of Civil and Environmental Engineering
Sean Raffuse, associate director of software and data, UC Davis Air Quality Research Center
Deborah Bennett, professor, Department of Public Health Sciences
Natalia Deeb-Sossa, professor, Chicana/o Studies

I CAN DO THAT

Daily 11 minute brisk walk enough to reduce risk of early death, say Cambridge researchers

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

One in ten early deaths could be prevented if everyone managed at least half the recommended level of physical activity, say a team led by researchers at the University of Cambridge.

In a study published today in the British Journal of Sports Medicine, the researchers say that 11 minutes a day (75 minutes a week) of moderate-intensity physical activity – such as a brisk walk – would be sufficient to lower the risk of diseases such as heart disease, stroke and a number of cancers.

Cardiovascular diseases – such as heart disease and stroke – are the leading cause of death globally, responsible for 17.9 million deaths per year in 2019, while cancers were responsible for 9.6 million deaths in 2017. Physical activity – particularly when it is moderate-intensity – is known to reduce the risk of cardiovascular disease and cancer, and the NHS recommends that adults do at least 150 minutes of moderate-intensity activity or 75 minutes of vigorous-intensity activity a week.

To explore the amount of physical activity necessary to have a beneficial impact on several chronic diseases and premature death, researchers from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge carried out a systematic review and meta-analysis, pooling and analysing cohort data from all of the published evidence. This approach allowed them to bring together studies that on their own did not provide sufficient evidence and sometimes disagreed with each other to provide more robust conclusions.

In total, they looked at results reported in 196 peer-reviewed articles, covering more than 30 million participants from 94 large study cohorts, to produce the largest analysis to date of the association between physical activity levels and risk of heart disease, cancer, and early death.

The researchers found that, outside of work-related physical activity, two out of three people reported activity levels below 150 min per week of moderate-intensity activity and fewer than one in ten managed more than 300 min per week.

Broadly speaking, they found that beyond 150 min per week of moderate-intensity activity, the additional benefits in terms of reduced risk of disease or early death were marginal. But even half this amount came with significant benefits: accumulating 75 min per week of moderate-intensity activity brought with it a 23% lower risk of early death.

Dr Soren Brage from the MRC Epidemiology Unit said: “If you are someone who finds the idea of 150 minutes of moderate-intensity physical activity a week a bit daunting, then our findings should be good news. Doing some physical activity is better than doing none. This is also a good starting position – if you find that 75 minutes a week is manageable, then you could try stepping it up gradually to the full recommended amount.”

Seventy-five minutes per week of moderate activity was also enough to reduce the risk of developing cardiovascular disease by 17% and cancer by 7%. For some specific cancers, the reduction in risk was greater – head and neck, myeloid leukaemia, myeloma, and gastric cardia cancers were between 14-26% lower risk. For other cancers, such as lung, liver, endometrial, colon, and breast cancer, a 3-11% lower risk was observed.

Professor James Woodcock from the MRC Epidemiology Unit said: “We know that physical activity, such as walking or cycling, is good for you, especially if you feel it raises your heart rate. But what we’ve found is there are substantial benefits to heart health and reducing your risk of cancer even if you can only manage 10 minutes every day.”

The researchers calculated that if everyone in the studies had done the equivalent of at least 150 min per week of moderate-intensity activity, around one in six (16%) early deaths would be prevented. One in nine (11%) cases of cardiovascular disease and one in 20 (5%) cases of cancer would be prevented.

However, even if everyone managed at least 75 min per week of moderate-intensity physical activity, around one in ten (10%) early deaths would be prevented. One in twenty (5%) cases of cardiovascular disease and nearly one in thirty (3%) cases of cancer would be prevented.

Dr Leandro Garcia from Queen’s University Belfast said: “Moderate activity doesn’t have to involve what we normally think of exercise, such as sports or running. Sometimes, replacing some habits is all that is needed. For example, try to walk or cycle to your work or study place instead of using a car, or engage in active play with your kids or grand kids. Doing activities that you enjoy and that are easy to include in your weekly routine is an excellent way to become more active.”

The research was funded by the Medical Research Council and the European Research Council.

What counts as moderate-intensity physical activity?

Moderate-intensity physical activity raises your heart rate and makes you breathe faster, but you would still be able to speak during the activity. Examples include:

Brisk walking
Dancing
Riding a bike
Playing tennis
Hiking

Reference
Garcia, L, Pearce, M, Abbas, A, Mok, A & Strain, T et al. Non-occupational physical activity and risk of cardiovascular disease, cancer, and mortality outcomes: a dose response meta-analysis of large prospective studies. British Journal of Sports Medicine; 27 Feb 2023; DOI: 10.1136/bjsports-2022-10566

JOURNAL

British Journal of Sports Medicine

DOI

10.1136/bjsports-2022-105669

METHOD OF RESEARCH

Systematic review

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Non-occupational physical activity and risk of cardiovascular disease, cancer, and mortality outcomes: a dose response meta-analysis of large prospective studies

ARTICLE PUBLICATION DATE

28-Feb-2023

Woodcocks have the brightest white feathers ever measured

Peer-Reviewed Publication

IMPERIAL COLLEGE LONDON

Woodcock in flight — IMAGE: WOODCOCK IN FLIGHT view more
CREDIT: JEAN-LOU ZIMMERMANN

The mainly brown woodcock uses its bright white tail feathers to communicate in semi-darkness, reflecting 30% more light than any other known bird.

These surprise findings, by a team led by an Imperial College London scientist, suggest there is much to learn about how birds that are most active at night or at dawn and dusk communicate.

Birds that are most active during the day often have colourful plumages, which they use to communicate information with each other. Birds that are most active at dawn and dusk or at night (‘crepuscular’), such as nightjars and woodcocks, tend to have less showy plumage, as while sleeping during the day they need to be camouflaged to avoid predators.

Rather than using showy plumages, it was thought that birds active during low light conditions instead used sounds or chemicals to communicate. However, many have bright white patches, which could be used in environments with very little natural light for communication if these are reflective enough.

The Eurasian woodcock, Scolopax rusticola, is primarily mottled brown, but has patches of white feathers on the underside of its tail. This means it only shows these patches when raising its tail or during courtship display flights.

However, as they are crepuscular, and so most active during low light, these white patches need to reflect as much light as possible to attract attention. To investigate how they might do this, the team studied the white tail feathers of Eurasian woodcock specimens from a collection in Switzerland.

They used specialised microscopy to image feather structure, spectrophotometry to measure the light reflectance, and models to characterise how photons of light interact with structures inside the feather. They were surprised to find the reflectance measurements showed the feathers reflected up to 55% of light – 30% more light than any other measured feather. The results are published today in Royal Society Interface.

Lead researcher Jamie Dunning, from the Department of Life Sciences (Silwood Park) at Imperial, said: “Bird enthusiasts have long known that woodcocks have these intense white patches, but just how white they are and how they function has remained a mystery. From an ecological perspective the intensity of the reflectance from these feathers makes sense – they need to hoover up all the light available in a very dimly lit environment, under the woodland canopy at night.”

Individual feathers are made of a central stem with protrusions called rami forming the bulk of the structure. The rami are held together by round Velcro-like ‘barbules’.

The team found that in the woodcock’s white tail feathers the rami are thickened and flattened, which both increases the surface area for light to bounce off, while also making it less likely light will pass between the feather barbs without being reflected.

There are two main ways surfaces are reflective. ‘Specular’ reflection is when light bounces off a smooth surface, like a mirror. ‘Diffuse’ reflectance scatters light rays in different directions. The thickened rami were found to be made up of a network of keratin nanofibers and scattered air pockets. This creates lots of interfaces that can scatter light, increasing the feathers’ diffuse reflectance.

Analysis of the feathers showed one final trick up the woodcock’s sleeve: the rami and barbules in the white woodcock feathers are arranged to create a venetian-blind-like effect that further enhances the surface area, by sitting at the optimum angle for light reflectance.

Principal Curator of Birds at the Natural History Museum Dr Alex Bond said: “This research is a brilliant combination of using museum specimens and cutting-edge tools to try and understand this phenomenon. Being able to see whether closely related species or species with similar ecology also had these incredibly white feathers was a key bit of figuring out the story.”

Optical microscopy image of the white tail region

SEM image fo the white feather tips

CREDIT

Liliana D’Alba