Archive for the ‘inverse square’ Category

“Anti-Radiaton” Mobile Phone Device TV Ads

Sunday, November 23rd, 2014

I might be a little out of he loop when it comes to what is on television.  I don’t really watch it all that often, and when I do, I usually am watching a DVR recording, so I don’t really sit through commercials.

Yet the other day I caught this on TV.  Seeing it really annoyed me a lot.  There’s nothing new in terms of the claims being made.  The product is certainly not the first of its type, but seeing these false claims being fed to the public through mainstream mass marketing is all the more infuriating.  The public becomes that much more indoctrinated with falsehoods and the producers of this product laugh all the way to the bank, as members of the public buy something that they don’t need and serves no purpose.

(Direct link to youtube video)

It’s a slick ad campaign. I have to admit it.

It starts off with a common, but completely inaccurate comparison. Yes, tobacco company executives did say that they didn’t think smoking caused cancer. But when it comes to evaluating the health risks of something, corporate executives are not really regarded as the most credible source of information, anyway. That is what scientific studies are for. In the case of tobacco smoking, the evidence that smoking increased the risk of cancer began to accumulate in the early 20th century, not that long after mass produced cigarettes made heavy daily smoking commonplace. By the 1930′s, the data was pretty solid. But even before tobacco smoking was linked to lung cancer, the mainstream medical establishment agreed that smoking was not a healthy habit and that it had negative impacts on respiratory health. (More info on this here)

In the case of RF radiation, we have some pretty conclusive data that would seem to indicate that, no, it does not cause cancer. RF radiation is non-ionizing and does not directly effect the chemistry of molecules like DNA. It therefore does not cause the kind of damage that could result in cancer. The subject of RF energy and health has been one of interest since at least the 1920′s. There have been numerous studies on mobile phones and potential health impacts, but even before they existed, we had decades worth of scientific data on the biological effects of microwaves.

That’s probably why they don’t do much in the way of citing studies. They do show a few snippets of statements of supposed harm from mobile phones. But that’s it.


Student Experiment Proves RF Kills Plants… or not…

Wednesday, December 18th, 2013

A recent story that has been making the rounds is one that seems to have it all:  brilliant young aspiring scientists, underdogs shaking up the world and fear of wifi and phone RF radiation.

Via the Daily Dot:

Your wireless router could be murdering your houseplants

Are you slowly killing your houseplants? Probably! But there might be a reason (other than neglect) why they’re all yellow and wilty: your Wi-Fi router.

An experiment by a handful of high school students in Denmark has sparked some serious international interest in the scientific community.

Five ninth-grade girls at Hjallerup School in North Jutland, Denmark, noticed they had trouble concentrating after sleeping with their mobile phones at their bedsides. They tried to figure out why. The school obviously doesn’t have the equipment to test human brain waves, so the girls decided to do a more rudimentary experiment.

They placed six trays of garden cress seeds next to Wi-Fi routers that emitted roughly the same microwave radiation as a mobile phone. Then they placed six more trays of seeds in a separate room without routers. The girls controlled both environments for room temperature, sunlight and water.

After 12 days, they found the garden cress seeds in the routerless room had exploded into bushy greenery, while the seeds next to the Wi-Fi routers were brown, shriveled, and even mutated. See for yourself:

Teacher Kim Horsevad told the Daily Dot that her students did the test twice with the same results. She was quick to point out that while the students did the experiment to test only one variable to the best of their ability, it is a high school experiment and this isn’t a professional study.

“Some of the local debate has been whether the effects were due the cress seeds drying up because of heat from the computers or Access Points used in the experiment, which is a suggestion I can thoroughly refute,” Horsevad said. “The pupils were painstakingly careful in keeping the conditions for both groups similar. The cress seeds in both groups were kept sufficiently moist during the whole experiment, and the temperature were controlled thermostatically. The computers were placed so that the heat would not affect the seeds, which was verified by temperature measurements. Still, there may be confounders which neither the pupils or I have been aware of, but I cannot imagine what they would be.”

Well, the photos are certainly pretty dramatic, but that does not mean that this should be considered hard confirmed science. After all, it was not peer reviewed and was done by high school students. That said, it’s the message rather than the messenger, and it’s not impossible that non-professionals could discover something to shake up the scientific world.



The Problems With This Experiment:

I am all for teaching students about science through hands-on demonstrations.  But in this case, there are a few things missing that are critical.   One of the most important is the basic idea that all experimental results should be viewed critically, but especially when they fly in the face of established science.  It can be summed up in the statement “extraordinary claims require extraordinary proof.”  If something is well established by science and your experiment seems to indicate something else, you should probably examine your experiment critically and repeat it (perhaps several times) before jumping to the conclusion that you have valid results.

Even professional scientists who try very hard to control their experiments.  For example, last year, scientists at a neutrino observatory in Italy took measurements which seemed to indicate the neutrinos were traveling faster than light.  They scratched their heads and checked their equipment repeatedly, repeated the experiment and finally concluded there were no flaws in their methodology and indeed they did record neutrinos exceeding the speed of light.  Then, however, they found there was a loose cable.  Oops.

Many studies have been done on RF radiation and biology and the results refute this.  Even if we assume that there could be an effect, it is all but unthinkable that it could be this dramatic.  If this was the case, then it would seem impossible that plants could grow near high power transmitters, which they clearly do.

Given that it flies in the face of logic and established science, anyone who gets these results should look at them with an abundance of caution and only consider them valid after repeated examination and conducting the experiment several times.

There are a few obvious things that could account for this:

Deplorably Bad Study on Mobile Phones And Saliva Published

Thursday, August 1st, 2013

I have been taking some time off.   I was not planning on posting again until mid next week, but this recent news story is so hideous, it was impossible for me to ignore it.   Recently a study was published which claims to have found marked differences in the saliva of heavy cell phone users.   This would be significant, if it were true, because it could show a direct biological effect on the saliva glands and, by extension, the possibility that this could lead to cancer or another condition.

It has been making the rounds in the mainstream media, as one might expect.  These kind of studies are almost guaranteed to generate a lot of press.

Via Science Daily:

Heavy Cell Phone Use Linked to Oxidative Stress
July 29, 2013 — Scientists have long been worried about the possible harmful effects of regular cellular phone use, but studies so far have been largely inconclusive. Currently, radiofrequency electromagnetic fields, such as those produced by cell phones, are classified as possibly carcinogenic to humans (Group 2B) by the International Agency for Research on Cancer (IARC). A new Tel Aviv University study, though, may bring bad news.

To further explore the relationship between cancer rates and cell phone use, Dr. Yaniv Hamzany of Tel Aviv University’s Sackler Faculty of Medicine and the Otolaryngology Head and Neck Surgery Department at the Rabin Medical Center, looked for clues in the saliva of cell phone users. Since the cell phone is placed close to the salivary gland when in use, he and his fellow researchers, including departmental colleagues Profs. Raphael Feinmesser, Thomas Shpitzer and Dr. Gideon Bahar and Prof. Rafi Nagler and Dr. Moshe Gavish of the Technion in Haifa, hypothesized that salivary content could reveal whether there was a connection to developing cancer.

Comparing heavy mobile phone users to non-users, they found that the saliva of heavy users showed indications of higher oxidative stress — a process that damages all aspects of a human cell, including DNA — through the development of toxic peroxide and free radicals. More importantly, it is considered a major risk factor for cancer.

The findings have been reported in the journal Antioxidants and Redox Signaling.

For the study, the researchers examined the saliva content of 20 heavy-user patients, defined as speaking on their phones for a minimum of eight hours a month. Most participants speak much more, Dr. Hamzany says, as much as 30 to 40 hours a month. Their salivary content was compared to that of a control group, which consisted of deaf patients who either do not use a cell phone, or use the device exclusively for sending text messages and other non-verbal functions.

Compared to the control group, the heavy cell phone users had a significant increase in all salivary oxidative stress measurements studied.

“This suggests that there is considerable oxidative stress on the tissue and glands which are close to the cell phone when in use,” he says. The damage caused by oxidative stress is linked to cellular and genetic mutations which cause the development of tumors.

The fact that this was even published leads me to believe that the journal in question must have extremely poor standards for peer review.

The number of study subjects is pretty small, and that itself would call into question any findings.   However, I will not bother critiquing the statistical distribution or significance of the study, because none of that actually matters, and doing so would dignify the validity of the study’s methods.   In fact, regardless of how dramatic and significant the findings of such a study are, they are irrelevant to the debate on mobile phones and health because of a massive foundational flaw in the study.


Feds Say They Cracked “X-Ray Weapon” Plot

Friday, June 21st, 2013

One thing I am always especially bothered by is when a big deal is made out of a trumped-up claim that the government has thwarted a major terror plot, that is, in fact, either nothing of the sort, or not a real danger.  These news stories come up constantly and seem to reenforce the idea that we need to give more power and money to the various agencies involved.   They tell us both that we need to fear the danger of evil plots and credit the authorities for their diligent work in keeping us safe.

A recent example is the supposed “X-Ray Weapon” that has supposedly been stopped.   While the individuals involved may well have been attempting to build a deadly device, their hair-brained scheme was not likely to be an acute danger to anyone.

Via the New York Times:

2 Men Charged in Bid to Make Deadly X-Ray Weapon
In April 2012, the authorities said, an industrial mechanic walked into a synagogue in Albany and announced his intention to build a weapon that could help Israel kill its enemies while they slept. He wanted to know if anybody would provide financial backing. Turned away, prosecutors said, he sought money from another source: a leader in the Ku Klux Klan in North Carolina.

Both the synagogue and the white supremacist group told the authorities about the man, Glendon Scott Crawford, who, until his arrest this week, devoted himself to building a weapon of the sort he had promised, the authorities said. The weapon was an X-ray-emitting device that could be activated by remote control, which he intended to use to kill Muslims, according to a criminal complaint unsealed in Federal District Court in Albany.

Mr. Crawford, who the authorities say works for General Electric in Schenectady and lives in Galway, N.Y., believed the device would enable him to secretly poison people with lethal doses of radiation from a safe distance, the authorities said. On Wednesday, federal prosecutors charged Mr. Crawford, 49, and an engineer, Eric J. Feight, 54, of Hudson, N.Y., whom the authorities described as a co-conspirator who works in industrial automation, with conspiring to provide support for the building of a weapon of mass destruction. The authorities say Mr. Crawford relied on Mr. Feight to design the weapon.

Mr. Crawford, the authorities said, conceived of a powerful X-ray device that could be placed in a truck and driven near a target. The driver would park, leave the area and activate the device, “killing human targets silently and from a distance with lethal doses of radiation,” the complaint against the men stated.

To add to the hysteria, other news stories have said the men planned to use the device to target President Barack Obama or that they were members of the Tea Party (a political movement which has been labeled as everything from racist to terrorist.)

There is a lot of questionable information in the reports.  For one thing, if they were actual KKK members, one wonders why they would be seeking support from Jews or looking to target the “Enemies of Israel,” since the Ku Klux Klan hates Jews.   They also reportedly lived in upstate New York, an area which does not have any active chapters of the Klan.   They may just have been garden variety racists who sympathized with hate groups.


Eleanor R Adair – 1927-2013

Saturday, May 18th, 2013

The name probably does not sound familiar, but Dr. Eleanor Adair should be remembered as one of the most important figures in advancing our understanding of the health effects of microwave radiation. She did some of the first controlled large-scale trails on humans, including herself, which helped establish the thermal effects of non-ionizing radiation.

As it turns out, I also live in the same town where she did, but sadly I did not know this until after her passing.

Obituary Via the New York Times:

Eleanor R. Adair, Microwave Proponent, Dies at 86

Eleanor R. Adair, a scientist who spent decades exposing monkeys and eventually people (including herself) to microwave radiation to determine whether it posed serious health risks — she concluded, emphatically and somewhat controversially, that it did not — died on April 20 in Hamden, Conn. She was 86.

The cause was complications of a stroke, her daughter, Margaret Adair Quinn, said.

In the early 1970s, Dr. Adair, who had done her doctoral work in sensory psychology, was pursuing an interesting but not necessarily provocative topic: how people and animals react physiologically to external heat sources. Yet over the next three decades — after her research led her to study heat generated through microwave radiation, which is used in microwave ovens and emitted at low levels by things like cellphones and electrical transmission lines — Dr. Adair became an increasingly prominent and firm voice of assurance that microwave radiation posed no health risk.

“All the emphasis that we need more research on power line fields, cellphones, police radar — this involves billions of dollars that could be much better spent on other health problems,” Dr. Adair said in an interview with The New York Times in 2001. “Because there is really nothing there.”

For some people close to the issue, those were fighting words.

Even as numerous studies have found that microwave ovens are safe and many scientists say there is no evidence that cellphones cause cancer or other health problems, the rising use of cellphones, wireless Internet signals and some medical and military devices has continued to raise questions about their risk. Last year, a panel of the World Health Organization listed microwave radiation as “possibly carcinogenic.” In March, the Federal Communications Commission announced that it would review its standards for cellphone use for the first time since 1996.

Some scientists do not use the term microwave radiation because they are concerned it is misleading and scares people unnecessarily. Microwave radiation is far weaker than the radiation in X-rays or gamma rays.

Advocates for more research count Dr. Adair in to a camp that focuses too much on heat or thermal effects from microwaves and is too quick to dismiss other ways microwaves might affect health.

“There’s something going on, and the question is what that is and whether it’s dangerous,” said Louis Slesin, the editor of Microwave News, a Web site that is often skeptical of the role industry and the military play in influencing health standards related to the issue. “Don’t let anyone tell you they know the answer to that question.”

Although Dr. Adair said she did not receive money from cellphone makers or industries whose products released microwave radiation, she served for five years late in her career as a senior scientist at the Air Force Research Laboratory in San Antonio. The Air Force uses radar that emits microwaves.


How Arthur Firstenberg Made His Neighbor’s Life A Living Hell

Thursday, February 21st, 2013

You may remember Arthur Fishtenberg.   Back in 2008, I described him as “The Jackass in the foil hat” for his various antics against various municipalities who dared to allow wireless devices to be used in their buildings.   According to Fishtenberg, a dental X-ray in 1982 somehow transformed him into an elector-hypersensitive and perpetually tortured victim of all things wireless.   Apparently he bounced around various communities in the US pulling this claim out to anyone who would listen.

Firstenberg has written several articles and a book about the dangers of wireless devices.  He has founded groups and is cited on a number of websites as a crusader for the rights of those who supposedly are harmed by these devices.  He has also filed many many lawsuits.

Apparently, in more recent years, Firstenberg has decided to take his battle directly to the individuals who dare to use RF-emitting devices in their own homes.  That’s what happened in 2010 when Raphaela Monribot had the misfortune of renting a home next to Arthur Firstenberg.   Miss Monribot, a graphic artist, didn’t do anything to cause conflict with her new neighbor other than daring to own a cell phone and a laptop computer.


“Smart Meters” – No, they do not make people sick

Wednesday, January 16th, 2013

Much to do has been made of the s0-called “smart meters” – electric meters that monitor the times electricity is used and transmit the data back to the utility company in order to bill customers based on the time they use electricity – charging higher rates for peak demand time and lower rates for electricity used during times of low demand.  The idea is that by doing so, they could encourage customers to better manage their electricity use and schedule energy intensive tasks for times of low demand – for example, washing and drying clothes.  This could help balance demand and lead to less need for more expensive peaking and load-following generation.   It also can supposedly save the customer money, but it often does not.

There are some valid reasons to oppose having a smart meter:

  • They could be considered part of an effort to shift the burden for reliable power and grid stability to the end customer.
  • Depending on your usage, they may not save you money and could result in your costs going up.
  • Life is complicated enough without having to worry about scheduling your tasks around the electric price schedule.
  • Once you get one installed, it’s likely to be impossible to get it removed, so if your electric company is asking for customers to volunteer for the new meters, it might be worth waiting to see if they really do end up saving money before taking the plunge.
  • You can tell a lot about someone from the times they use electricity (what days of the week they work, when they get up, when they leave for work, when they get home, when they go to sleep, when they are away from home etc)  Not all utilities have been very forthcoming about how they treat the information and whether they consider it private.  A telemarketer would definitely like to know what time would be good to call and bother you.   Even if the utility company does not sell the information, the government could certainly get it, and these days, at least in the US, the authorities have been acting like search warrants are obsolete.
  • The utility company may charge you a fee to install or for rental of the unit.  Not all utilities have been forthcoming about this, and it would be especially irritating if it turns out that the meter does not save you any money, AND you had to pay for it.

For all of these reasons, if my utility company were to offer the option of having a smart meter or opting out, I would opt out, at least until the meters had been installed for a few months and it was possible to find out whether other customers really did experience savings and did not end up getting targeted advertisements for insomnia medication or to have pizza delivered right at the time they have dinner.

But there is also a completely bogus reason to oppose smart meters: fears of radiation.   It’s ridiculous, not only unproven but completely out of line with decades of understanding of non-ionizing radiation.   Despite this, claims that smart meters are causing everything from cancer to headaches have become rampant.


San Fransisco Takes Another Crack At Mobile Phone Warning

Sunday, July 24th, 2011

A few months ago, a law requiring cell phones sold in San Fransisco to carry a warning label failed to pass the city council. Now it seems they are trying again. It may sound a bit odd that a city would require this – things like product safety are usually legislated on the national level. This is, however, San Fransisco, and so they’re a lot better than everyone else and want us to all know that they’re much more progressive and special, and also, their farts don’t smell. (that was sarcasm, in case you didn’t catch that)

This time the law is likely to pass, because everyone supports it, since if they don’t, it proves that they are just a shill for the evil big corporations that want to eat your children.

Via PC Magazine:

San Francisco Gives Cell-Phone Radiation Law Another Try

The San Francisco Board of Supervisors has approved a bill that would require a warning at stores that sell cell phones about the possible hazards of cell-phone radiation.

Last June, the City of San Francisco tentatively approved a bill that would have required merchants who sold cell phones within the city of San Francisco to display the “Specific Absorption Rate,” an FCC-mandated specification of radiation, next to the phones. Failure to comply would result in fines of between $100 to $300.

The bill approved this week would amend that bill with new provisions. Interim Mayor Ed Lee must still sign it into law.

In July 2010, however, the CTIA filed suit against the city, arguing that officials had no right to hand down regulations on an issue already addressed by the Federal Communications Commission.

There has been no definitive link that scientists have found linking the radiation emitted by cell phones to cancer. In late May, the World Health Organization classified mobile phones as a possible risk for a specific type of cancer in humans.


The new bill would mitigate the 2010 bill by proposing instead that customers would be notified of the dangers of cell-phone radiation, which would represent a strengthening of the law, as it includes an educational component, said Supervisor John Avalos.

“We are amending this ordinance…that would instead of having a rating per make and model of cell phone at point of sale, we would have a sign that merchants would provide in the stores close to the cell phones,” Avalos said. “I would say that cell phone emit radio frequencies and that they would also have to provide at the point of sale — they would have to provide at the point of sale a document sharing — to share with buyers on how to protect themselves from radiofrequency emissions.

“Those measures you can take to protect yourself, include using a headset instead of having the phone next to your ear, or keeping the cell phone in a casing that is less conductive of radiofrequency and there are other measures as well,” Avalos said.


Did Airport Scanners Give TSA Agents Cancer? NO, Absolutely Not!

Friday, July 1st, 2011

Lets get something straight: I don’t like the TSA. They’re not very good at keeping air travel secure and their searches are invasive, annoying and time consuming. They make air travel miserable. I don’t like their “body scanners” either. They’re very expensive, of limited value in actually protecting the traveling public and they can be a very unpleasant experience for those forced to use them or have a full body pat-down.

But they are not giving TSA Agents or anyone else cancer, as it has been alleged recently.

Via Time Magazine:

Did Airport Scanners Give Boston TSA Agents Cancer?

Could radiation from full-body scanners be responsible for a “cancer cluster” among airport security workers? That’s what Transportation Security Administration union representatives in Boston have claimed.

Now, the Washington-based Electronic Privacy Information Center (EPIC) has obtained documents from the Department of Homeland Security, which EPIC says provide evidence that the government failed to properly test the safety of full-body scanners at airports, and dismissed concerns from airport agents about excessive exposure to the machines’ radiation.

The documents, which include emails, radiation test results and radiation studies, were obtained through a Freedom of Information Act lawsuit filed by EPIC. The advocacy group says they indicate that Homeland Security “publicly mischaracterized” safety findings by the National Institute of Standards and Technology (NIST), by suggesting that NIST had “affirmed the safety” of full body scanners.

But in an email obtained by EPIC, a NIST official stated that the agency had not tested the scanners for safety and does not in fact do product testing. Rather NIST had merely measured the radiation dose from a single machine against the standard of what is considered an acceptable. It had not done the rigorous product testing required to determine safety over time.

In the case of the Boston “cluster,” however, too little is yet known to suggest a link: neither EPIC nor the union reps have indicated what types of cancers the security agents in Boston have been diagnosed with. The scanners’ radiation, which typically targets the skin and the muscles right beneath it, would most logically be tied to a common type of skin cancer called basal cell carcinoma.

The actual amount of radiation produced by backscatter x-ray systems is very low. While there has been some dispute about the accuracy of the measurements, since they were not independently verified for each and every machine under all possible conditions, even by the most liberal estimates, the maximum dose that a person might get from working near such a machine is on par with that one receives from flying in a commercial airliner. The radiation is also very low energy or “soft” so it does not have much penetrating power at all. It is barely able to penetrate the skin and would not result in much exposure to internal organs.

Even if the dose were ten times higher than the worst case estimates, it would not result in any noticeable increase in cancer in a small group, such as the TSA employees at one airport.


WHO Drops the Ball on Cell Phones and Cancer

Tuesday, May 31st, 2011

Cell Phones don’t cause cancer. RF radiation does not cause cancer. Those statements I am willing to stand behind. If you don’t believe me, please use the search function on this site. I can assure you I have plenty of posts with citations of both the theoretical reasons why non-ionizing radiation does not cause cancer and the studies that have shown no link.

There’s a lot of pressure to say that they do, however. Claiming cell phones cause cancer sells books and magazines. Some dishonest people have made a whole career out of telling these lies. They become media darlings because everyone loves to hate the “big companies” and to talk about how some poor little guy is being kept down by those evil powers that be. Groups make a lot of money too. Especially when the emotion-charged issue of children is dragged into the mix, dishonest charities can grab headlines and donations. Groups that contribute nothing useful to the world are treated as charities while paying their top executives hundreds of thousands of dollars a year or more.

Oh, and by the way, I’m not afraid to name names when it comes to these dishonest people and groups: Lennart Hardell, George Carlo, Devra Davis, The Environmental Health Trust, Bioinitiative, EMF-Health, Microwave News. (there, so sue me. I’d love to see you in court about this)

Thankfully the WHO has been one organization that has been steadfast about the fact that there is no evidence to indicate a relationship between RF radiation and cancer. There are lots of claims, a few very poorly controlled experiments but no evidence, and this is despite some enormous studies and decades of trying.

Unfortunately, however, the WHO has recently made some more ambiguous statements on the issue. Bowing to pressure from those with a financial stake and those stupid enough to believe them, the WHO has now stated that mobile phone radiation is “possibly carcinogenic” – in other words, there’s no absolutely certain empirical evidence that shows beyond any shadow of a doubt that there’s no remote possibility that maybe somehow by some unknown mechanism, radio waves might have once in the history of the universe caused a cell to become cancerous. (They also claim to base this in part on largely discredited studies linking glioma, a certain form of brain cancer to mobile phones.)

Still, this is a bad idea. It’s a horrible message to send out. The problem is not that it’s entirely scientifically invalid to say that something is very remotely possible, but how politicians, the media and society take such statements. It sometimes seems that research scientists don’t fully understand just how badly a statement can and will be butchered and taken out of context.

This non-story has already spawned over one thousand media reports. Here are a few to provide a taste of just how this plays out:

Los Angeles Times: Experts say cellphones are possibly carcinogenic
Financial Times: WHO signals mobile phone cancer fears
Dallas Morning News: World Health Organization says cellphones might cause brain cancer
The Australian: Risk of brain tumour from mobile phone use is similar to pesticide DDT, petrol exhaust and coffee
Bellfast Telegraph: Brain cancer warning over mobiles
Newsday: Panel sees possible cellphone-cancer link
PC Magazine: WHO Finds Tentative Link Between Cell Phones, Cancer
Seattle Post Intelligencer – Experts: Cell phone use raises risk of cancer

Those are, of course, just a few.

A couple comments about this shameful reporting:
What the hell is a “tentative link?” Does that mean that they don’t have a shred of evidence but are pretty sure they will at some point?

Also, in case you did not know: DDT has never been conclusively linked to cancer in humans, though there were some conflicting studies about chronic exposure in prepubescent girls and breast cancer later, the link appears very weak. There’s not even the slightest evidence that DDT is related to brain cancer.

Coffee has never been linked to brain cancer in any way shape or form, though some studies have found a small risk of increased bladder cancer in very heavy coffee drinkers. The evidence of this is considered inconclusive, in part because the increase was very small and not found by all studies of coffee and bladder cancer. There may be other confounding factors at play.

Automobile exhaust may be carcinogenic depending on the circumstances, such as the fuel burned, the exposure levels etc. There’s little evidence that the combustion byproducts of properly and completely burned gasoline are directly carcinogenic. Of course, these would be mostly carbon dioxide and water.