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Published on Leave a comment on What is “Seeding” the Microbiomes of Babies Born By C-section?

The mother is an important source of the first microbiome for infants by "seeding" the baby's microbiome - from the vaginal birth and then breastfeeding. However, research finds that infants born by C-section acquire bacteria commonly found on skin (Staphylococcus, Corynebacterium, and Propionibacterium) rather than the bacteria acquired during a vaginal birth.

This study examined the source of the skin-type bacteria found on C-section babies. The researchers analyzed the dust from operating rooms (which they collected right after C-sections) and found that it contains deposits of human skin bacteria and human skin flakes. The researchers point out that "Humans shed up to 37 million bacterial genomes into the environment per hour." Operating rooms are occupied by humans, lack natural ventilation, and even though they are regularly cleaned, the humans using the operating rooms shed bacteria and skin flakes. From Microbiome:

The first microbial environment of infants born by C-section: the operating room microbes

Newborns delivered by C-section acquire human skin microbes just after birth, but the sources remain unknown. We hypothesized that the operating room (OR) environment contains human skin bacteria that could be seeding C-section born infants. To test this hypothesis, we sampled 11 sites in four operating rooms from three hospitals in two cities. Following a C-section procedure, we swabbed OR floors, walls, ventilation grids, armrests, and lamps....The bacterial content of OR (operating room) dust corresponded to human skin bacteria, with dominance of Staphylococcus and Corynebacterium. Diversity of bacteria was the highest in the ventilation grids and walls but was also present on top of the surgery lamps. 

We conclude that the dust from ORs, collected right after a C-section procedure, contains deposits of human skin bacteria. The OR microbiota is the first environment for C-section newborns, and OR microbes might be seeding the microbiome in these babies. 

In the present study, we used 16S rRNA gene sequencing to show that OR dust, collected right after a C-section procedure, contains bacteria similar to human skin microbiota. Previous studies using culture-dependent methods also showed that over 85 % of air samples from ORs had skin-like bacteria which were mostly coagulase-negative staphylococci and Corynebacterium. These airborne skin-bacteria could be from individuals present during C-section but could also be shed by cleaning personnel between operations.

In our study, 30 % of samples failed to yield sufficient DNA sequences to be analyzed. While there are no published data on the microbiota in operating rooms using 16S rRNA gene sequencing, very few bacteria (average 3.3–3.5 CFU/10 cm2) were detected in ORs after regular decontamination using standard culturing methods, consistent with the low sequence numbers in our study.

In addition, we found that the microbiota of OR samples was more similar to human skin microbiota than oral microbiota and that OR dust contains deposits of human skin flakes. These results reveal that while the use of surgical masks has limited effectiveness at curtailing oral microbial shedding, skin flakes from individuals present during C-section and/or from cleaning personnel between operations could be a more influential factor contributing to the structure of OR microbiota.

Our SourceTracker analysis results suggest that the OR microbes could play a role in seeding infants born by C-section. C-section born infants, in particular, may be solely receiving this inoculum, while vaginally born infants have exposure to vaginal bacteria. The results of these further studies could be relevant to the possible effects on the priming of the immune system by skin bacteria from environmental sources as the primordial inoculum seeding the infant microbiome. This might be relevant to the increased risk of immune diseases observed in C-section born infants.

Published on Leave a comment on When Do Football Players Recover From Concussions?

New research showed that eight days after a concussion, the concussed athletes (football players) looked and felt like they had recovered (clinical recovery), but MRIs showed that there were still neurophysiological abnormalities (significant blood flow decrease) in their brains. They did not look at if and when the blood flow returned to normal, but that research also needs to be done.

It is very disturbing to look at both this research and also the finding that the off-season is not enough for high school football players to recover from the repeated hits (not concussions, but sub-concussive hits) that they receive during the football season (Nov. 24, 2015 post). Do student football players really know and understand the dangers to their brains from the repeated hits and also concussions that occur in football? From Medical Xpress:

Reduced blood flow seen in brain after clinical recovery of acute concussion

Some athletes who experience sports-related concussions have reduced blood flow in parts of their brains even after clinical recovery, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA). The results suggest a role for MRI in determining when to allow concussed athletes to return to competition.

Decisions to clear concussed athletes to return to action are typically based on symptoms and cognitive and neurological test results. However, there is increasing evidence that brain abnormalities persist beyond the point of clinical recovery after injury. To find out more, researchers from the Medical College of Wisconsin in Milwaukee studied concussed football players with arterial spin labeling, an advanced MRI method that detects blood flow in the brain.

Dr. Wang and colleagues studied 18 concussed players and 19 non-concussed players. They obtained MRI of the concussed players within 24 hours of the injury and a follow-up MRI eight days after the injury and compared results with those of the non-concussed players. Clinical assessments were obtained for both groups at each time point, as well as at the baseline before the football season.

The concussed players demonstrated significant impairment on clinical assessment at 24 hours post-injury, but returned to baseline levels at eight days. In contrast to clinical manifestation, the concussed players demonstrated a significant blood flow decrease at eight days relative to 24 hours post-injury, while the non-concussed players had no change in cerebral blood flow between the two time points.

"In eight days, the concussed athletes showed clinical recovery," Dr. Wang said. "However, MRI showed that even those in clinical recovery still had neurophysiological abnormalities. Neurons under such a state of physiologic stress function abnormally and may become more susceptible to second injury." "For years, we've relied on what athletes are telling us," Dr. McCrea said. "We need something more objective, and this technology may provide a greater measurement of recovery."

Published on Leave a comment on Brains of Teen Football Players Don’t Fully Heal During the Off Season

This past week there was discussion of the number of high school football players that die annually while playing football (at least 5). But the bigger risk - because it involves so many players - is the damage to brains that occurs from concussions and from just being hit in football. The response from football enthusiasts is that there are safeguards now - that football players don't play after a concussion until they "heal" (show no obvious symptoms). But do they really heal? And much of the damage is from repeated hits, without having a concussion (sub-concussive blows or hits), what about the damage from that?

This study found that repeated head hits in football can cause changes in brain chemistry and metabolism, even in high school players not diagnosed with concussions. And even after the lengthy off-season (somewhere between two and five months after the season has ended)—the majority of players are still showing that they had not fully recovered. The researchers also made it clear that 2 weeks is not enough time to heal from a concussion. Scary long-term implications - what is happening to brains that never truly heal from past seasons as the players start playing in the next season? From Futurity:

High School Football: Teen Brains Don't Heal During Offseason

Brain scans of high school football players taken before, during, and after the season raise concerns they don’t fully recover from repeated head hits. The researchers used an imaging technique called proton magnetic resonance spectroscopy (1H MRS) to study the brains of 25 high school football players and compared them to the brains of teenagers involved in non-contact sports. The findings suggest repeated head hits in football can cause changes in brain chemistry and metabolism, even in players not diagnosed with concussions. 

“We are seeing damage not just to neurons, but also to the vasculature and glial cells in the brain,” says Eric Nauman, professor of mechanical engineering, basic medical sciences, and biomedical engineering at Purdue University. “I was particularly disturbed that when you get to the offseason—we are looking somewhere between two and five months after the season has ended—the majority of players are still showing that they had not fully recovered.”

The 1H MRS data provide details about the blood flow, metabolism, and chemistry of neurons and glial cells important for brain function. The data also revealed a “hypermetabolic response” during the preseason, as though the brain was trying to heal connections impaired from the previous season. “We found that in the preseason for the football players in our study, one part of the brain would be associating with about 100 other regions, which is much higher than the controls,” says Thomas Talavage,  professor of electrical and computer engineering and biomedical engineering and co-director of the Purdue MRI Facility.

“The brain is pretty amazing at covering up a lot of changes. Some of these kids have no outward symptoms, but we can see their brains have rewired themselves to skip around the parts that are affected.”

One of the research papers shows that knowing a player’s history of specific types of hits to the head makes it possible to accurately predict “deviant brain metabolism,” suggesting that sub-concussive blows can produce biochemical changes and potentially lead to neurological problems, which indicates a correlation between players taking the heaviest hits and brain chemistry changes.

The data shows that the neurons in the motor cortex region in the brains of football players produced about 50 percent less of the neurotransmitter glutamine compared to controls. “We are finding that the more hits you take, the more you change your brain chemistry, the more you change your brain’s ability to move blood to the right locations,” Nauman says.

“Recent proton magnetic resonance spectroscopy studies argue that the recommended two-week window of rest is insufficient for full metabolic recovery after concussion,” Nauman says. “Those returning to play prior to full recovery could incur a second concussion with symptoms and metabolic changes more lasting than the first.”

Published on Leave a comment on Breast Milk and Preserving Sight In Preemies

Another excellent reason to breastfeed premature infants - to increase the odds of preventing retinopathy of prematurity (ROP), which is the reason preemies can go blind. It occurs when blood vessels in the retinas of premature infants start to grow out of control. If the abnormal growth continues, the retinas detach, and this can cause blindness.

Sadly, an ROP epidemic occurred in the 1940s and early 1950s when hospital nurseries began using excessively high levels of oxygen in incubators to save the lives of premature infants. During this time, ROP was the leading cause of blindness in children in the US. In 1954, scientists funded by the National Institutes of Health determined that the relatively high levels of oxygen routinely given to premature infants at that time were an important risk factor, and that reducing the level of oxygen given to premature babies reduced the incidence of ROP.

Nowadays ROP is a leading cause of childhood blindness in developed countries. A large US study found that in extremely preterm infants with a gestational age of 22 to 28 weeks, the incidence of ROP was 59% (96% at 22 weeks and 32% at 28 weeks). ROP is considered a  multifactorial disease, and risk factors such as prematurity, low birth weight, oxygen therapy, and oxidative stress have been associated with its development.

This recent study was a meta-analysis of five studies (of 2208 pre-term infants), and it found that the overall incidence of ROP was reduced among infants fed human breast milk compared with those fed formula. The best results in preventing severe ROP was in babies fed exclusively breast milk (up to 90% reduction) or mainly human breast milk feeding. It is thought that breast milk may protect against the development of ROP because of its antioxidant and immune-protective properties.  Note that studies involving donor milk were not included because past studies did not find any advantage for donor milk over formula. This may be possibly related to loss of the breast milk microbes (breast milk normally contains up to 700 species of bacteria) during processing (pasteurizing/heat treatment of milk for 30 minutes) and storage of donor milk. From NPR:

Mother's Milk May Help Prevent Blindness In Preemies

If Stevie Wonder had been born three decades later, we might never have gotten "Superstition" and "Isn't She Lovely" — but the musician might never have gone blind, either. Born premature, Wonder developed retinopathy of prematurity, an eye disease that afflicts more than half of babies born before 30 weeks of gestation.Though treatments were developed in the 1980s, about 400 to 600 U.S. children and 50,000 children worldwide still go blind every year from the condition. Now a study suggests that number could be slashed by more than half if all those preemies received their mothers' milk.

The study, actually a combined analysis of five studies from 2001 through 2013, found that preemies receiving human milk from their mothers had 46 to 90 percent lower odds of retinopathy of prematurity (ROP), depending on how much milk they received and how severe the ROP was. The studies were observational, so they cannot show that breast milk directly caused the lower risk.

Of the infants who develop ROP, most recover and develop well without treatment, but about 10 percent develop severe ROP, increasing their risk of blindness, Chiang said. About half of those infants need treatment, which will prevent blindness in 80 to 90 percent of them.

The new research analyzed the outcomes of 2,208 preterm infants based on whether they received exclusive human milk, any human milk, mainly human milk (more than 50 percent), exclusive formula, any formula or mainly formula. The study did not include donor milk, so all the milk was the mother's pumped or hand-expressed breast milk.

Infants who exclusively received breast milk had 89 percent reduced odds of severe ROP compared to infants who received any formula. Infants who received a mixture of breast milk and formula had roughly half the odds of developing severe ROP compared to infants exclusively receiving formula. The analysis included a very large older study that had found no reduced risk for ROP from breast milk, but most infants in that study received less than 20 percent breast milk.

Until the 1940s and 1950s, ROP did not exist because infants born prematurely rarely survived, Chiang said. As doctors learned to how to keep these tiny babies, usually little more than 3 pounds at birth, alive, they discovered that the blood vessels in their retinas would often start to grow out of control. If the abnormal growth continued, their retinas detached, causing blindness.

The cause of ROP isn't entirely understood, but scientists believe oxidative stress can stimulate the abnormal growth of the blood vessels. Providing preemies with oxygen is often key to their survival, but that oxygen exposure might lead to ROP, according to Jianguo Zhou, a neonatologist in Shanghai, and lead author of the study.

Published on Leave a comment on American Academy of Pediatrics: End Routine Antibiotic Use in Animals

The American Academy of Pediatrics released a new report that the overuse of antibiotics in animals poses a real health risk to children. Giving routine antibiotics to animals leads to antibiotic resistant bacteria  - which means that antibiotics may not work when given to people. Most of the antibiotics sold in the U.S. each year - 80 percent- are used in animals that people than eat. The great majority of antibiotics given to animals are the same ones given to humans.The main way to ensure that the meat that you are purchasing is antibiotic-free is to buy meat labeled organic. And to buy organic dairy products (milk, butter, cheese, cream). Note that the reason routine use of antibiotics in animals has not been stopped so far in the USA is due to agriculture industry lobbying. From Medical Xpress:

Pediatricians' group urges cuts in antibiotic use in livestock

Overuse of antibiotics in farm animals poses a real health risk to children, the American Academy of Pediatrics warns in a new report.This common practice is already contributing to bacterial resistance to medicines and affecting doctors' ability to treat life-threatening infections in kids, according to the paper published online Nov. 16 in the journal Pediatrics.

"The connection between production uses of antibiotics in the agricultural sector to antibiotic resistance is alarming," said Victoria Richards, an associate professor of medical sciences at the Quinnipiac University School of Medicine in Hamden, Conn. She believes the danger is "not only for infants and children but other vulnerable populations, such as the pregnant and the older individuals."

As the academy explained in its warning, antibiotics are often added to the feed of healthy livestock to boost growth, increase feed efficiency or prevent disease. However, the practice can also make antibiotics ineffective when they are needed to treat infections in people. Some examples of emerging antibiotic germs include methicillin-resistant staphylococcus aureus (MRSA), C.difficile, and highly resistant strains of the tuberculosis bacterium. Each year, more than 2 million Americans develop antibiotic-resistant infections and more than 23,000 die from these infections, the academy said. And in 2013, the highest incidence of such infections was among children younger than 5, federal government statistics show. 

"Children can be exposed to multiple-drug resistant bacteria, which are extremely difficult to treat if they cause an infection, through contact with animals given antibiotics and through consuming the meat of those animals," report author Dr. Jerome Paulson, immediate past chair of the academy's executive committee of the Council on Environmental Health, said in an academy news release."Like humans, farm animals should receive appropriate antibiotics for bacterial infections," he said. "However, the indiscriminate use of antibiotics without a prescription or the input of a veterinarian puts the health of children at risk."

Spaeth noted that the U.S. Centers for Disease Control and Prevention, as well as the World Health Organization, have both called for a curbing of antibiotic use in animals. But the authors of the new report expressed concern over resistance from the agriculture and farming industry to such measures.

Published on Leave a comment on Exposure to Animals In First Year of Life and Lower Risk of Asthma

Labrador Retriever image Other studies have found this same association - that living with a dog or farm animal has health benefits such as lower risk of allergies and asthma. In a Swedish nationwide study looking at over a million children, the association between early exposure to dogs and farm animals and the risk of asthma was evaluated. All children born in Sweden from January 1, 2001, to December 31, 2010 were included. The researchers found that exposure to dogs and farm animals during the first year of life reduces the risk of asthma in children at age 6 years. From Science Daily:

Early contact with dogs linked to lower risk of asthma

A team of Swedish scientists have used national register information in more than one million Swedish children to study the association of early life contact with dogs and subsequent development of asthma. This question has been studied extensively previously, but conclusive findings have been lacking. The new study showed that children who grew up with dogs had about 15 percent less asthma than children without dogs.

A total of more than one million children were included in the researchers' study linking together nine different national data sources, including two dog ownership registers not previously used for medical research...."Earlier studies have shown that growing up on a farm reduces a child's risk of asthma to about half. We wanted to see if this relationship also was true also for children growing up with dogs in their homes. Our results confirmed the farming effect, and we also saw that children who grew up with dogs had about 15 percent less asthma than children without dogs.

"These kind of epidemiological studies look for associations in large populations but do not provide answers on whether and how animals could protect children from developing asthma. We know that children with established allergy to cats or dogs should avoid them, but our results also indicate that children who grow up with dogs have reduced risks of asthma later in life. Thanks to the population-based design, our results are generalizable to the Swedish population, and probably also to other European populations with similar culture regarding pet ownership and farming" says Catarina Almqvist Malmros, senior author on the study, Paediatrician at Astrid Lindgren Children's Hospital and Professor in Clinical epidemiology at Dept of Medical Epidemiology and Biostatistics at Karolinska Institutet, Stockholm.

Published on Leave a comment on Reducing Sugar Improves Health

This study showed that children reducing sugar consumption (but not fruits), and without reducing calories, after 10 days improved all sorts of metabolic health markers: blood pressure, LDL cholesterol, triglycerides, liver function, fasting blood glucose, and insulin levels. As one of the researchers said: "I have never seen results as striking or significant in our human studies; after only nine days of fructose (sugar) restriction, the results are dramatic and consistent from subject to subject." Once again, not all calories are the same.

On average, the obese children in this study had been getting about 27 percent of their daily calories from sugar, and during the study period it was lowered to about 10 percent of daily calories. By comparison, the average American takes in about 15 percent, though children typically consume much more than this in part because they have the highest intake of sugar-sweetened beverages. In February of this year, the federal government’s Dietary Guidelines Advisory Committee recommended that Americans limit their intake of added sugars to no more than 10 percent of daily calories. From Medical Xpress:

Obese children's health rapidly improves with sugar reduction unrelated to calories

Reducing consumption of added sugar, even without reducing calories or losing weight, has the power to reverse a cluster of chronic metabolic diseases, including high cholesterol and blood pressure, in children in as little as 10 days, according to a study by researchers at UC San Francisco and Touro University California.

"This study definitively shows that sugar is metabolically harmful not because of its calories or its effects on weight; rather sugar is metabolically harmful because it's sugar," said lead author Robert Lustig, MD, MSL, pediatric endocrinologist at UCSF Benioff Children's Hospital San Francisco. "This internally controlled intervention study is a solid indication that sugar contributes to metabolic syndrome, and is the strongest evidence to date that the negative effects of sugar are not because of calories or obesity."

Metabolic syndrome is a cluster of conditions—increased blood pressure, high blood glucose level, excess body fat around the waist, and abnormal cholesterol levels—that occur together and increase risk of heart disease, stroke, and diabetes. Other diseases associated with metabolic syndrome, such as non-alcoholic fatty liver disease and type 2 diabetes, now occur in children—disorders previously unknown in the pediatric population.

In the study, 43 children between the ages of 9 and 18 who were obese and had at least one other chronic metabolic disorder, such as hypertension, high triglyceride levels or a marker of fatty liver, were given nine days of food, including all snacks and beverages, that restricted sugar but substituted starch to maintain the same fat, protein, carbohydrate, and calorie levels as their previously reported home diets.....The study menu restricted added sugar (while allowing fruit), but substituted it by adding other carbohydrates such as bagels, cereal and pasta so that the children still consumed the same number of calories from carbohydrate as before, but total dietary sugar was reduced from 28 to 10 percent, and fructose from 12 to 4 percent of total calories, respectively. The food choices were designed to be "kid food" - turkey hot dogs, potato chips, and pizza all purchased at local supermarkets, instead of high sugar cereals, pastries, and sweetened yogurt.

Children were given a scale and told to weigh themselves everyday, with the goal of weight stability, not weight loss. When weight loss did occur (a decrease of an average of 1 percent over the 10-day period but without change in body fat), they were given more of the low-sugar foods."When we took the sugar out, the kids started responding to their satiety cues," said Schwarz. "They told us it felt like so much more food, even though they were consuming the same number of calories as before, just with significantly less sugar. Some said we were overwhelming them with food."

After just 9 days on the sugar-restricted diet, virtually every aspect of the participants' metabolic health improved, without change in weight. Diastolic blood pressure decreased by 5mm, triglycerides by 33 points, LDL-cholesterol (known as the "bad" cholesterol) by 10 points, and liver function tests improved. Fasting blood glucose went down by 5 points, and insulin levels were cut by one-third. "All of the surrogate measures of metabolic health got better, just by substituting starch for sugar in their processed food—all without changing calories or weight or exercise," said Lustig. "This study demonstrates that 'a calorie is not a calorie.' Where those calories come from determines where in the body they go. Sugar calories are the worst, because they turn to fat in the liver, driving insulin resistance, and driving risk for diabetes, heart, and liver disease."

Published on Leave a comment on Secret Hazard of Nail Polish

Beware of nail polish because it may be contaminating your body with an endocrine disrupting chemical.  A study co-authored by researchers at Duke University and Environmental Working Group (EWG) detected evidence of a common nail polish chemical called triphenyl phosphate, or TPHP, in the bodies of every woman who volunteered to paint her nails for the study.There is growing evidence suggesting that TPHP may affect hormone regulation, metabolism, reproduction and development. Unfortunately, even if it is not listed on the label, it may still be in the product. It is also used as a fire retardant (and the evidence from studies says to avoid fire retardants). Go to the EWG site for more on nail polish brands.From Environmental Working Group (EWG):

Duke-EWG Study Finds Toxic Nail Polish Chemical In Women’s Bodies

Researchers at Duke University and Environmental Working Group have found evidence of a suspected endocrine-disrupting chemical widely used in popular nail polishes in the bodies of more than two-dozen women who participated in a biomonitoring study. The study, published today in Environment International, found that all women had a metabolite of triphenyl phosphate, or TPHP, in their bodies just 10 to 14 hours after painting their nails. Their levels of diphenyl phosphate or DPHP, which forms when the body metabolizes TPHP, had increased by nearly sevenfold.

According to EWG’s Skin Deep® cosmetics database, more than 1,500 nail products including polishes made by Sally Hansen, OPI and Wet N Wild, contain TPHP. Click here for a list of brands that list TPHP as an ingredient. More nail polishes may contain undisclosed TPHP.  The Duke-EWG study tested 10 polishes for TPHP and found the chemical in eight of them. Two of the eight with TPHP did not list the ingredient on their labels.  ...continue reading "Secret Hazard of Nail Polish"

Published on Leave a comment on Nanotubes Found in Lungs of Children

Scary study results showing what may scientists have long feared - that carbon nanotubes are being released into the environment and getting into our bodies with unknown health effects. The researchers point out that fine particulate matter (PMs) from air pollution penetrate lower airways and are associated with adverse health effects even with low concentrations and that carbon nanotubes are part of this fine particulate matter. Here they discussed how catalytic converters may convert carbon monoxide into carbon nanotubes during the process of converting carbon monoxide into safer emissions. The problem with carbon nanotubes is that they are so small - so small that we inhale them, but can't cough them out. Carbon nanotubes can be envisioned as one-atom thick sheets of carbon atoms that have been rolled into tubes with diameters as small as 1 nm and lengths up to several centimeters. And scientists are concerned that they may have inflammatory effects on the lungs (similar to what asbestos does). Of course the long-term studies have not yet been done....Because once again, technological advances have outpaced any safety sudies. The researchers studied the lung cells of children with asthma, but it is unclear whether the carbon nanotubes had any effect on or caused their asthma.

Two additional areas of serious concern regarding carbon nanotubes: (1) many tires now contain carbon nanotubes, and with abrasion (wear and tear) the nanotubes are released into the air (air pollution), and (2) the tire crumb fill used in synthetic turf fields. People, including athletes and developing children, are playing on these fields and whatever is in the tires (toxic chemicals, lead, etc. and carbon nanotubes) is being released into the air, and inhaled and ingested by those playing and exercising on the synthetic turf. From Futurity:

Nanotubes Found in Lungs of French Kids

Cells taken from the airways of Parisian children with asthma contained man-made carbon nanotubes—just like the kind found in the exhaust pipes of vehicles in Paris. The researchers report in the journal EBioMedicine that these samples align with what has been found elsewhere in US cities, in spider webs in India, and in ice cores. The research in no way ascribes the children’s conditions to the nanotubes, says Rice University chemist Lon Wilson, a corresponding author of a new paper describing the work. But the nanotubes’ apparent ubiquity should be the focus of further investigation, he adds.

“We know that carbon nanoparticles are found in nature,” Wilson says, noting that round fullerene molecules like those discovered at Rice are commonly produced by volcanoes, forest fires, and other combustion of carbon materials. “All you need is a little catalysis to make carbon nanotubes instead of fullerenes.”

Carbon nanotubes (the long rods) and nanoparticles (the black clumps) appear in vehicle exhaust from tailpipes of cars in Paris.

 

 

 

 

 

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Carbon inside a lung cell vacuole takes the form of nanotubes (rods) and nanoparticles (black clumps). Credit: Both photos Fathi Moussa, Paris-Saclay Univ.

 

A car’s catalytic converter, which turns toxic carbon monoxide into safer emissions, bears at least a passing resemblance to the high-pressure carbon monoxide, or HiPco, process to make carbon nanotubes, he says. “So it is not a big surprise, when you think about it,” Wilson adds.

The team—led by Wilson, Fathi Moussa of Paris-Saclay University, and lead author Jelena Kolosnjaj-Tabi, a graduate student at Paris-Saclay—analyzed particulate matter found in the alveolar macrophage cells (also known as dust cells) that help stop foreign materials like particles and bacteria from entering the lungs. 

The cells were taken from 69 randomly selected asthma patients aged 2 to 17 who underwent routine fiber-optic bronchoscopies as part of their treatment. For ethical reasons, no cells from healthy patients were analyzed, but because nanotubes were found in all of the samples, the study led the researchers to conclude that carbon nanotubes are likely to be found in everybody.

The study notes but does not make definitive conclusions about the controversial proposition that carbon nanotube fibers may act like asbestos, a proven carcinogen. But the authors reminded that “long carbon nanotubes and large aggregates of short ones can induce a granulomatous (inflammation) reaction.”

The study partially answers the question of what makes up the black material inside alveolar macrophages, the original focus of the study. The researchers found single-walled and multiwalled carbon nanotubes and amorphous carbon among the cells, as well as in samples swabbed from the tailpipes of cars in Paris and dust from various buildings in and around the city. “The concentrations of nanotubes are so low in these samples that it’s hard to believe they would cause asthma, but you never know,” Wilson says. “What surprised me the most was that carbon nanotubes were the major component of the carbonaceous pollution we found in the samples.”

The nanotube aggregates in the cells ranged in size from 10 to 60 nanometers in diameter and up to several hundred nanometers in length, small enough that optical microscopes would not have been able to identify them in samples from former patients. The new study used more sophisticated tools, including high-resolution transmission electron microscopy, X-ray spectroscopy, Raman spectroscopy, and near-infrared fluorescence microscopy to definitively identify them in the cells and in the environmental samples.

“We collected samples from the exhaust pipes of cars in Paris as well as from busy and non-busy intersections there and found the same type of structures as in the human samples,” Wilson says. “It’s kind of ironic. In our laboratory, working with carbon nanotubes, we wear facemasks to prevent exactly what we’re seeing in these samples, yet everyone walking around out there in the world probably has at least a small concentration of carbon nanotubes in their lungs,” he says. The researchers also suggest that the large surface areas of nanotubes and their ability to adhere to substances may make them effective carriers for other pollutants.

Published on Leave a comment on Eat Organic Foods to Lower Pesticide Levels

Several studies have found that when children eat organic foods, especially fruits and vegetables, the amount of pesticides in their bodies declines significantly. Most organophosphorus pesticides have been phased out for residential use, but they are still widely used in agriculture, and so these pesticides are detected in both foods and people.

This latest study looked at 20 children living in urban Oakland, Calif., and 20 in the agricultural community of Salinas, about 100 miles south. The children (between 3 - 6 years of age) ate a conventional diet for four days and an organic diet for seven days and then returned to conventional foods for five days. Their urine was collected daily and analyzed for pesticides, specifically by looking at pesticide metabolites (pesticide breakdown products).

Several classes of pesticides were frequently detected, for they were found in more than 72 percent of their urine samples, and 2,4-D was detected in 90% of samples. Of the six most frequently detected pesticides, two decreased by nearly 50 percent when children were on the organic diet, and levels of the common herbicide 2,4-D fell by 25 percent. Amounts of some pesticides were not significantly lower on the organic diet, but these were pesticides associated with use around homes for pest control, and not on foods (e.g., pyrethroids, diazinon, malathion).

Bottom line: eat as many organic foods as possible to lower pesticide levels in the  body. To further reduce pesticide levels in the body - avoid pesticide use around the home and garden. Instead, use least toxic IPM (Integrated Pest Management) or organic pest control and organic gardening.

From Medical Xpress: Organic produce means reduced pesticides in kids, study shows

New research out of the Center for Environmental Research and Children's Health at UC Berkeley shows that switching from conventional to organic fruits and vegetables, even for just a few days, significantly reduces pesticide levels in children's bodies.

Twenty children in Oakland, California and 20 in Salinas, California, all 3 to 6 years old, had their urine tested for 16 days during the study. For the first four, they ate conventional produce, for the next seven their diet was organic, and then conventional for the last five. The levels of several pesticides that showed up in daily testing dropped by one-quarter to one-half during the organic stretch.

Excerpts from the original study from Environmental Health Perspectives: Effect of Organic Diet Intervention on Pesticide Exposures in Young Children Living in Low-Income Urban and Agricultural Communities

Recent organic diet intervention studies suggest that diet is a significant source of pesticide exposure in young children....We aimed to determine whether consuming an organic diet reduced urinary pesticide metabolite concentrations in 40 Mexican-American children, 3–6 years of age, living in California urban and agricultural communities. In 2006, we collected urine samples over 16 consecutive days from children who consumed conventionally grown food for 4 days, organic food for 7 days, and then conventionally grown food for 5 days. We measured 23 metabolites, reflecting potential exposure to organophosphorous (OP), pyrethroid, and other pesticides used in homes and agriculture.

For six metabolites with detection frequencies > 50%, adjusted geometric mean concentrations during the organic phase were generally lower for all children, and were significant for total dialkylphosphates (DAPs) and dimethyl DAPs (DMs; metabolites of OP insecticides) and 2,4-D (2,4-dichlorophenoxyacetic acid, a herbicide), with reductions of 40%, 49%, and 25%, respectively (p < 0.01). Chemical-specific metabolite concentrations for several OP pesticides, pyrethroids, and herbicides were either infrequently detected and/or not significantly affected by diet.

Although most residential uses of many organophosphorus (OP) pesticides, including chlorpyrifos and diazinon, have been phased out since the mid-2000s due to potential health risks to children, they have continued to be used in agriculture [U.S. Environmental Protection Agency (EPA) 2000, 2001]. The use of OP pesticides in agriculture could result in ingestion of residues in food, and recent studies suggest that dietary intake of produce and juices may account for a significant proportion of OP pesticide exposure in young children (Lu et al. 2006b, 2008; Morgan et al. 2005; Smith-Spangler et al. 2012; Wilson et al. 2003). Some of the best evidence supporting these findings includes results from diet intervention studies where significant reductions in excreted urinary pesticide metabolites were observed in young children when they consumed an organic diet (Lu et al. 2006b, 2008)....The lower urinary pesticide metabolite concentrations found in children eating organic diets is consistent with food residue monitoring data that has shown lower pesticide residue levels in organic versus conventionally grown food [Baker et al. 2002; U.S. Department of Agriculture (USDA) 2008].

Other factors associated with children’s cumulative pesticide exposures include socioeconomic status and location of residence. For example, low-income children may experience higher exposures to pesticides, particularly pyrethroids, because of poor housing quality and associated pest infestations and home pesticide use (Bradman et al. 2005a; Quirós-Alcalá et al. 2011; Whyatt et al. 2002). Children living in agricultural areas, compared with children living in non-agricultural suburban areas, are exposed to higher ambient and residential contamination from drift or volatilization from nearby agricultural applications and take-home residue by farmworking parents (Bradman et al. 2011; Harnly et al. 2009;Lu et al. 2000; Quirós-Alcalá et al. 2011).

Our finding that an organic diet was not associated with a significant reduction in pyrethroid metabolite (3-PBA) excretion for all children is not surprising given that these pesticides are primarily used in and around homes and not commonly applied to food crops; the finding is also consistent with Lu et al. (2006a), who reported that residential use is a more significant pyrethroid exposure factor for children than a conventional diet. 

Several studies indicate that dietary intake is a potential route of exposure for herbicides.....Overall, these studies indicate that 2,4-D may be present in food and support our finding that the lower levels observed in our population during the organic diet phase were attributable to lower dietary exposure.

In summary, consistent with other studies, urinary 2,4-D and two measures of OP pesticide exposure (total DMs and total DAP metabolites) were lower in children eating an organic diet. Other frequently detected metabolites for pyrethroids, diethyl OP pesticides, and the herbicide metolachlor were not significantly lower during the organic diet phase. Further, several compound-specific herbicide and OP pesticide metabolites had low detection frequencies, indicating that diet was not an important exposure source for these pesticides (e.g., diazinon, malathion) in this population. Last, independent of diet, most frequently detected metabolites were generally higher in Salinas compared with Oakland children, with DMs and metolachlor at or near significance (p = 0.06 and 0.03, respectively), suggesting additional sources of pesticide exposure for children living in agricultural communities.