Above is a photograph I took of the particulate white ‘dust’ I found on my bedside table; the circle of white light is the flashlight I used.
Emergency Services Declare ‘Major Disaster’ after Mass Thunderstorm Asthma Event
Hospitals across Victoria have been left reeling after an unprecedented number of people suddenly fell acutely sick on Monday evening, in what is believed to be a mass incident of “thunderstorm asthma”. Ambulance Victoria was flooded with calls after a storm hit Melbourne shortly before 6pm, prompting a “major disaster response” from emergency services. The demand was so great that Ambulance Victoria ran out of ambulances and had to call in police officers, non-emergency patient vehicles and field doctors trained for disasters to help with transporting acute patients to hospital.
State health commander Paul Holman said in his 40 years as a paramedic he had never seen an event like it. Mr Holman said it is thought the storm brought with it an increase in irritants, leading to the huge wave of patients suffering from breathing issues. He said the majority of the patients were so sick they needed to be taken to hospital (rather than being treated at the scene) and at one stage there were 190 people waiting for assistance. “Every ambulance and ambulance manager was recalled,” he said. “It was an unprecedented night.
Tiny particles may pose big risk: Some nanoparticles commonly added to consumer products can significantly damage DNA.
Anne Trafton | MIT News Office / April 8, 2014
Thousands of consumer products — including cosmetics, sunscreens, and clothing — contain nanoparticles added by manufacturers to improve texture, kill microbes, or enhance shelf life, among other purposes. However, several studies have shown that some of these engineered nanoparticles can be toxic to cells.
A new study from MIT and the Harvard School of Public Health (HSPH) suggests that certain nanoparticles can also harm DNA. This research was led by Bevin Engelward, a professor of biological engineering at MIT, and associate professor Philip Demokritou, director of HSPH’s Center for Nanotechnology and Nanotoxicology.
The researchers found that zinc oxide nanoparticles, often used in sunscreen to block ultraviolet rays, significantly damage DNA. Nanoscale silver, which has been added to toys, toothpaste, clothing, and other products for its antimicrobial properties, also produces substantial DNA damage, they found.
The findings, published in a recent issue of the journal ACS Nano, relied on a high-speed screening technology to analyze DNA damage. This approach makes it possible to study nanoparticles’ potential hazards at a much faster rate and larger scale than previously possible.
The Food and Drug Administration does not require manufacturers to test nanoscale additives for a given material if the bulk material has already been shown to be safe. However, there is evidence that the nanoparticle form of some of these materials may be unsafe: Due to their immensely small size, these materials may exhibit different physical, chemical, and biological properties, and penetrate cells more easily.
“The problem is that if a nanoparticle is made out of something that’s deemed a safe material, it’s typically considered safe. There are people out there who are concerned, but it’s a tough battle because once these things go into production, it’s very hard to undo,” Engelward says.
The researchers focused on five types of engineered nanoparticles — silver, zinc oxide, iron oxide, cerium oxide, and silicon dioxide (also known as amorphous silica) — that are used industrially. Some of these nanomaterials can produce free radicals called reactive oxygen species, which can alter DNA. Once these particles get into the body, they may accumulate in tissues, causing more damage.
“It’s essential to monitor and evaluate the toxicity or the hazards that these materials may possess. There are so many variations of these materials, in different sizes and shapes, and they’re being incorporated into so many products,” says Christa Watson, a postdoc at HSPH and the paper’s lead author. “This toxicological screening platform gives us a standardized method to assess the engineered nanomaterials that are being developed and used at present.” The researchers hope that this screening technology could also be used to help design safer forms of nanoparticles; they are already working with partners in industry to engineer safer UV-blocking nanoparticles. Demokritou’s lab recently showed that coating zinc oxide particles with a nanothin layer of amorphous silica can reduce the particles’ ability to damage DNA.
Until now, most studies of nanoparticle toxicity have focused on cell survival after exposure. Very few have examined genotoxicity, or the ability to damage DNA — a phenomenon that may not necessarily kill a cell, but one that can lead to cancerous mutations if the damage is not repaired.
A common way to study DNA damage in cells is the so-called “comet assay,” named for the comet-shaped smear that damaged DNA forms during the test. The procedure is based on gel electrophoresis, a test in which an electric field is applied to DNA placed in a matrix, forcing the DNA to move across the gel. During electrophoresis, damaged DNA travels farther than undamaged DNA, producing a comet-tail shape.
Measuring how far the DNA can travel reveals how much DNA damage has occurred. This procedure is very sensitive, but also very tedious. …
Zinc oxide and silver produced the greatest DNA damage in both cell lines. At a concentration of 10 micrograms per milliliter — a dose not high enough to kill all of the cells — these generated a large number of single-stranded DNA breaks.
Silicon dioxide, which is commonly added during food and drug production, generated very low levels of DNA damage. Iron oxide and cerium oxide also showed low genotoxicity.
… The most common routes that engineered nanoparticles follow into the body are through the skin, lungs, and stomach, so the researchers are now investigating nanoparticle genotoxicity on those cell types. They are also studying the effects of other engineered nanoparticles, including metal oxides used in printer and photocopier toner, which can become airborne and enter the lungs.
The research was funded by MIT’s Center for Environmental Health Sciences, the National Institute of Environmental Health Sciences, the National Science Foundation, and the National Institutes of Health. Other authors of the study are MIT graduate student Jing Ge, Harvard graduate student Joel Cohen, and Harvard postdoc Georgios Pyrgiotakis.
NASA EOSDIS Worldview
The Caspian Sea (two above) http://go.nasa.gov/2gcq5fq http://go.nasa.gov/2fzK58b
New Zealand (two above) http://go.nasa.gov/2fzNxj7
North of Antarctica & south of Australia (above & below) http://go.nasa.gov/2fzMIXz
Above Antarctica & south of the tip of South America (two above)