Environment

How does air pollution destroy our sense of smell?

Published

1 year ago

06/03/2023

pouyan

How does air pollution destroy our sense of smell? Losing the sense of smell or anosmia can have a significant impact on our quality of life, and researchers say that air pollution plays a role in causing it.

How does air pollution destroy our sense of smell?

In this article we’re going to read about how does pollution destroy our sense of smell . The sense of smell is one of our richest and broadest windows to the world around us, which plays a vital role in what we taste and our social interactions, and even helps us recognize possible dangers. But the threat in the air we breathe can destroy our sense of smell.

Covid-19 has shown many people what it is like to lose the sense of smell. Loss of the sense of smell, which is called “anosmia”, can have a significant impact on our well-being and quality of life. But while a sudden respiratory infection may lead to a temporary loss of this important sense, the sense of smell may gradually deteriorate over many years due to air pollution.

Exposure to PM2.5 (the collective name for particulate air pollution that comes mainly from burning fuel in our vehicles, power plants, and homes) has previously been linked to olfactory disorders, but usually only in certain environments, writes the BBC. Industrial or occupational. But new research reveals the true scale of olfactory impairment caused by air pollution and the potential harm caused by the pollution we breathe in every day. The findings of this study are important for all of us.

In the lower part of the brain, just above the nasal cavities, is the olfactory bulb. This sensitive tissue has nerve endings and is essential for the diverse image we get of the world with the help of the sense of smell. The olfactory bulb is also our first line of defense against viruses and pollutants entering the brain. But when repeatedly exposed to harmful factors, this defense slowly weakens.

“Our data show a 1.6- to 1.7-fold increased risk of developing anosmia in conditions of persistent particulate matter pollution,” says Murugapan Ramanathan, a nasal disease specialist at Johns Hopkins School of Medicine in Baltimore. Ramanathan has been curious about whether there is a connection between suffering from anosmia and the level of air pollution where people live. The simple question that Ramanathan wanted to answer was this: Is the prevalence of anosmia higher in people who live in areas with higher PM2.5 pollution?

Until recently, there was little scientific research on this topic. A Mexican study from 2006 used the smell of coffee and oranges to show that residents of Mexico City, who are often exposed to air pollution, have a poorer sense of smell on average than people living in rural areas of the country.

With the help of colleagues including Genevieve Zhang, an epidemiologist who created a map of air pollution data in the Baltimore area, Ramanathan conducted a study using data from 2,690 patients who visited Johns Hopkins Hospital over a four-year period. About 20% of the mentioned patients had anosmia and most of them did not smoke. Smoking affects the sense of smell.

PM2.5 levels were higher in neighborhoods where patients with anosmia lived, compared to healthy control group participants. Even when the effect of age, sex, ethnicity, body mass index, and alcohol and tobacco use were taken into account, the same result was obtained: even a small increase in exposure to ambient PM2.5 may be associated with anosmia.

These findings have been repeated in studies in other regions of the world. For example, a recent study in Brescia in northern Italy showed that the more teenagers and young adults were exposed to nitrogen dioxide (another pollutant produced when fossil fuels are burned, especially from vehicle engines), the more sensitive their noses were to odors. Another annual study in São Paulo, Brazil, also found that people who lived in areas with higher particle pollution had a poorer sense of smell.

How does air pollution destroy our sense of smell?

According to Ramanathan, there are two possible paths. One is that some pollution particles pass through the olfactory bulb and directly enter the brain and cause inflammation. “The olfactory nerves are in the brain, but there’s an opening at the base of the skull where small nerve fibers enter the nose,” says Ramanathan.

In 2016, a team of British researchers found the following metallic particles in human brain tissue that appeared to have passed through the olfactory bulb. Barbara Maher, a professor of environmental science at Lancaster University who led the study, said at the time that the particles were similar to those found in polluted air near busy streets. (Fireplaces and wood-burning stoves were also other possible sources).

Maher’s study shows that when tiny metal particles enter the brain, they can be toxic and cause oxidative brain damage that damages neural pathways; Although this is still theoretical. Another possible mechanism, says Ramanathan, may not even require pollution particles to enter the brain. Particles of pollution by constantly hitting the olfactory bulb, cause inflammation and damage to the nerves and destroy them slowly. Think of this situation as coastal erosion, where sand and salt waves gradually erode the shoreline. Let’s say those airwaves are full of pollution and the coastline is our nasal nerves.

Therefore, it is not surprising that anosmia mostly affects older people whose noses have been exposed to air pollution for a longer period. Interestingly, none of the Johns Hopkins patients lived in areas with excessive air pollution. Most of them lived in the green areas of Maryland, and none of them lived in highly polluted areas. This shows that even low levels of air pollution can cause problems in the long run.

A similar study was conducted separately by the Center for Aging Research at the Karolinska Institute in Stockholm. Postdoctoral researcher Ingrid Ekström was puzzled by findings from the early 2000s that showed more than 5.8 percent of adults in Sweden had anosmia and 19.1 percent had some form of smell disorder.

Knowing that the rate of anosmia is higher among the elderly, Ekstrom and colleagues designed a study using 3363 patients aged 60 years and older. Using sticks that gave off 16 common household odors, participants were scored based on the number of odors they could correctly identify.

As in the Baltimore study, participants’ home addresses were mapped based on urban air pollution, and here, too, a strong correlation was seen between higher pollution levels and poorer olfactory strength. “They had been exposed to pollution throughout their lives,” says Ekström. We don’t know exactly when their olfactory disorder started.” But he is confident that long-term exposure to pollution, even at low levels, has caused people’s olfactory disorders.

In 2021, the World Health Organization changed its health-based guidelines for the maximum annual average exposure to PM2.5 particles, changing it from 10 micrograms per cubic meter to 5 micrograms per cubic meter.

Stockholm, the capital of Sweden, is one of the few big cities in the world that is below the set level with an annual average of 4.2 micrograms per cubic meter. In contrast, Pakistan’s Islamabad has an annual average PM2.5 of 41.1 micrograms per cubic meter, while this average in Bloemfontein, South Africa is 42.3 micrograms per cubic meter.

This makes the Stockholm findings even more important: even Stockholm residents lose their sense of smell due to low pollution levels; How much worse can this problem be in areas where pollution levels are high? It’s also a reminder of how local pollution can be, both outdoors and indoors. Cooking and heating methods may expose some households to higher levels of pollution than their neighbors.

Meanwhile, modern combustion methods from vehicle engines to new wood stoves can produce tiny nanoparticles that barely register in PM2.5 readings, but are small enough to enter our bloodstream and brain tissue directly.

Air pollution is the cause of a quarter of deaths from heart disease and stroke and almost half of the deaths from lung diseases.

Maybe our sense of smell does not seem so alarming compared to the mentioned diseases. But Ramanathan and Ekström warn that the sense of smell and the problems caused by its lack are more important than they think.

Related Topics:air pollution environment

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Environment

Climate change slows down the rotation of the earth!

Published

4 weeks ago

29/03/2024

pouyan

Researchers at the University of California, San Diego have written in a new paper that climate change significantly alters the Earth’s rotation and disrupts time.

Climate change slows down the rotation of the earth!

Climate change seems to be disrupting time.

According to the Washington Post, the melting of polar ice caps due to global warming affects the rotation of the Earth and can also affect accurate timekeeping.

The planet is not going to stop, nor is it going to speed up so much that everyone is launched into space, but timing is an exact science in a high-tech society. For this reason, humans were forced to invent the concept of “leap second” more than half a century ago by observing slight changes in the Earth’s rotation.

Climate change has now complicated these calculations. In just a few years it may be necessary to introduce a “negative leap second” into the calendar to bring the planet’s rotation into line with the Universally Coordinated Clock.

University of California, San Diego (UCSD) geophysicist Duncan Agnew said: Global warming actually measurably affects the rotation of the entire Earth. Things are happening that have not happened before.

The main problem with timing

Chronology has traditionally had an astronomical basis. The earth is a kind of clock. In simpler times, the planet made one complete revolution on its axis, and everyone called that a day.

However, technologists are looking for difficult levels of accuracy. Atomic clocks already tell us what time it is. The goal of people who want to do things exactly right is to make sure that atomic time is perfectly aligned with astronomical time. For example, GPS-equipped satellites must know exactly where the earth is below them and exactly what time it is in order to accurately get you from home to your destination.

But the earth does not rotate at a constant speed. Our planet is in a complex gravitational dance with the moon, sun, ocean tides, its atmosphere, and the motion of the solid inner core.

Agnew noted that the Earth’s core is not accessible for close inspection and is a bit like a black box. By drilling into certain areas of the sea floor, geophysicists can understand details about the planet’s interior. Last year, it was reported that scientists had detected changes in the Earth’s rotation that seemed to match the 70-year fluctuations in the core’s rotation.

When scientists try to describe what the Earth is doing at any given moment, they have to account for a lot of tilting and shaking.

Earth is no longer slowing down. In fact, the Earth has sped up quite a bit, and not a single leap second has been added since the end of 2016.

Melting of the Antarctic and Greenland ice sheets transports the melt water towards the equator. This process increases the equatorial bulge of the planet. Meanwhile, land compressed by ice rises at the poles, making the Earth more spherical. National Institute of Standards and Technology (NIST) physicist Judah Levine, who was not involved in this research, said: These two changes in the shape of the planet have opposite effects on its rotation.

Agnew’s new paper says that although the core makes the planet spin faster, changes in the planet’s shape caused by warming climates slow it down. Without this effect, the overall acceleration of the planet’s rotation might require timers to enter a negative leap second at the end of 2026, Agnew wrote. Due to climate change, this may not be necessary until 2029.

This research was published in “Nature” magazine.

Environment

A device that produces endless energy from soil

Published

3 months ago

18/01/2024

pouyan

A new fuel cell harnesses energy from soil-dwelling microbes to power sensors, harvesting nearly unlimited energy from the soil. In this article we will talk about a device that produces endless energy from soil.

A device that produces endless energy from soil

A team from Northwestern University has demonstrated a new way to generate electricity. They introduced a device the size of a book that sits on top of the soil and collects the force generated by microbes breaking down the soil (as long as there is carbon in the soil).

According to New Atlas, microbial fuel cells, as their name suggests, have been around for over 100 years. They work a bit like a battery, with an anode, cathode, and electrolyte, but instead of taking electricity from a chemical source, they work with bacteria that naturally donate electrons to nearby conductors.

This newly invented fuel cell relies on the ubiquitous natural microbes in the soil to generate energy.

A microbial fuel cell (MFC) or biological fuel cell is a biochemical system that produces electric current by mimicking the activity of bacteria that occurs in nature. A microbial fuel cell is a type of biochemical fuel cell system that generates electric current by diverting electrons produced from the microbial oxidation of reduced compounds (also known as fuel or electron donors) on the anode to oxidizing compounds (known as oxidizing agents or also known as electron acceptor) on the cathode through an external electrical circuit.

Fuel cells can be divided into two general categories “mediated and non-mediated”. The first fuel cells, introduced in the early 20th century, used a mediator, a chemical substance that transfers electrons from the bacteria in the cell to the anode. Non-intermediate fuel cells emerged in the 1970s. In this type of fuel cell, bacteria usually have electrochemically active proteins such as cytochromes on their outer membrane that can transfer electrons directly to the anode.

Northwestern University researchers note the durability of their powerful fuel cell and have shown its ability to withstand various environmental conditions, including dry soil and flood-prone areas.

The issue so far has been to supply them with water and oxygen while they are buried in the soil. Although these devices have existed as a concept for more than a century, their uncertain performance and low power output have hampered efforts to put them into practice, especially in low-power conditions, says Northwestern University graduate student Bill Yen, who led the project. The humidity had stopped.

So the team set out to create several new designs aimed at providing cells with continuous access to oxygen and water and succeeded with a cartridge-shaped design that sits vertically on a horizontal disk.

A disk-shaped carbon-felt anode sits horizontally at the bottom of the device and goes deep into the soil, where it can capture electrons as microbes break down the soil.

Meanwhile, the conductive metal cathode is placed vertically above the anode. So the lower part goes deep enough to access the deep soil moisture, while the upper part is flush with the ground and a fresh air gap runs the entire length of the electrode, and a protective cap on top prevents soil from falling and It becomes waste and cuts off the cathode’s access to oxygen. Part of the cathode is also covered with a water-insulating material so that when water is present, a hydrophobic part of the cathode is still in contact with oxygen for the fuel cell to work.

The researchers used a waterproof material on the surface of the cathode, which allows it to work even during flooding and ensures gradual drying after immersion in water.

“These microbes are everywhere,” says George Wells, lead author of the study. They live in the soil everywhere now and we can use very simple engineered systems to get electricity from them. We’re not going to power entire cities with this energy, but we can capture very small amounts of energy to fuel essential, low-consumption applications.

Also, chemicals left over from batteries can potentially seep into the soil. This new technology is an environmentally friendly alternative that reduces environmental concerns associated with hazardous battery components and is also non-combustible.
The design performed consistently well in tests at varying levels of soil moisture, from completely waterlogged to relatively dry, and produced, on average, about 68 times more energy than its sensors needed to operate. It was also strong enough to survive extreme changes in soil moisture.

As with other sources of long-term electricity generation, such as diamond beta-voltaic batteries made from nuclear waste, the amount of electricity produced here is not enough to start a car or power a smartphone, but rather to power small sensors that can be used for long periods. work for a long time without needing to replace the battery regularly.

In addition, the researchers attached the soil sensor to a small antenna to enable wireless communication. This allowed the fuel cell to transmit data to a nearby station by reflecting existing radio frequency signals.

It is noteworthy that this soil fuel cell has a 120% better performance than similar technology.
Bill Yen says: “If we imagine a future with trillions of devices, we can’t make them all out of lithium, heavy metals, and toxins that are dangerous to the environment.” We need to find alternatives that can provide small amounts of energy to power a decentralized network of devices. In our search for a solution, we turned to soil microbial fuel cells, which use special microbes to break down soil and use that small amount of energy. As long as there is organic carbon in the soil for microbes to break down, our fuel cells can potentially survive.

Therefore, sensors like these can be very useful for farmers looking to monitor various soil elements including moisture, nutrients, pollutants, etc., and to use a technology-based precision agriculture approach. So if you put several of these devices around your farm, they can generate data for you for years, maybe even decades.

It should be mentioned that according to the research team, all the components of this device can be purchased from hardware stores. Therefore, there is no problem in the supply chain or materials for the widespread commercialization of this product.

This research was published in the ACM Journal on Interactive, Mobile, Wearable, and Ubiquitous Technologies.

Environment

What if all the fish in the ocean disappeared?

Published

3 months ago

17/01/2024

pouyan

Earth’s vast oceans cover most of our planet’s surface and are teeming with life, hosting an amazing variety of plants, microbes, worms, corals, crabs and fish, whales, and more. So what if all the fish in the ocean disappeared?

What if all the fish in the ocean disappeared?

The ocean is full of fish so they account for the second largest amount of carbon (the stuff that makes up living things) in the entire animal kingdom. They are right behind the group of insects and crustaceans. So what if all the fish in the ocean disappeared?

Most people only interact with the ocean from a beach or a boat, so it’s difficult to estimate how many fish there are across the oceans, but the oceans are teeming with fish from the surface to their depths, says SA.

These fish exist in different types and sizes. From the tiny sardines, guppies, and blennies you might see in coral reefs to the tuna and whale sharks you find in the open ocean.

These fish play a variety of roles in their ecosystem that support the lives of other creatures around them, and if they were to disappear one day, the ocean would look very different.

This article was written by Corey Evans, a scientist at Rice University who studies fish, their diversity, and all the ways they contribute to ocean environments.

Fish as food

Fishes play an important role in ocean ecosystems as both predators and prey. Thousands of species across ocean and terrestrial ecosystems, including humans, rely on fish for food.

In coral reef ecosystems, small fish are eaten by larger fish and other marine animals. This means that small fish form the base of the food web. They provide energy for larger fish and other organisms.

In the aquatic world, many birds, mammals, and reptiles eat fish and rely on them as an essential source of protein.

Even land plants can benefit from the presence of fish. On the West Coast of the United States, salmon returning to small rivers after spending several years at sea act as a conveyor belt of nutrients.

Salmon not only feed the animals that catch them, such as bears but also provide nutrients to the plants that line the rivers.

Studies have shown that some plants get up to 70% of their nitrogen from salmon that die on or near river banks.

Humans also depend on fish as a food source. Fish and other seafood are an important source of protein for nearly three billion people on Earth. The human population around the world has been eating fish for thousands of years.

Conservation of habitats by fish

Fish do more than just feed. Because fish themselves forage, they can create and maintain important habitats for other organisms. In coral reef ecosystems, herbivorous fish control the growth of algae by continuously feeding on them.

Without the help of these herbivorous fish, the algae would grow rapidly and suffocate the coral, effectively destroying it.

One of the types of herbivorous fish is the parrot fish, which feeds directly on corals. At first, this may seem bad for corals, but parrotfish feeding on them can actually increase the growth rate of a coral colony.

In addition, parrotfish excrement is especially nutritious for corals. Parrotfish poop also forms part of the beautiful white sand beaches you may have enjoyed on family vacations.

Other fish also create habitats for other animals and affect their environment by stirring up the sand as they feed. By moving the sand around, they expose small creatures hidden in the sand that other animals can eat.

Despite the fact that many types of fish are confined to the ocean, their presence can be felt in many habitats. They can directly and indirectly affect the lives of organisms that depend on them for food and shelter.

So if it weren’t for fish, the earth would gradually lose its beautiful white sand beaches, coral reef ecosystems would become overrun with algae, many people would run out of food to eat, and we would lose some of the most fascinating creatures on our beautiful planet.