Trust your doctor, not the Internet, is the message from scientists this week, as a study finds 9 out of 10 Wikipedia medical entries contain errors. Scientists in the U.S. compared Wikipedia entries for health related issues such as heart disease, lung cancer, depression and diabetes with peer-reviewed research. They found most articles contain “many errors”.

The concept of Wikipedia allows people to create edit, and delete entries, which increases the likelihood of mistakes. Wikimedia UK, the British arm of Wikipedia, said it was “crucial” that people with health concerns spoke to their GP first. Though the articles can be altered by anybody, there are volunteers from the medical profession who check pages for inaccuracies, reports expathealth.org

Wikipedia is the sixth most popular website for research said the authors of the study, published in the Journal of the American Osteopathic Association. Researchers found up to 70% of medical students and 47% of physicians use the tool.

The researchers wrote, “Physicians and medical students who currently use Wikipedia as a medical reference should be discouraged from doing so because of the potential for errors.”

The study looked at articles for the 10 most costly conditions in America, including asthma, back problems and osteoarthritis. The articles were printed and analysed on 25 April 2012 and the researchers found 90% made statements which contradicted the latest medical research.

Errors found included an entry which stated to correctly diagnose high blood pressure three high readings needed to be taken over time. This is incorrect and could lead to a dangerous delay in treatment said doctors. Another entry claimed antidepressants were not beneficial for children, but according to the researchers, this is incorrect and could prevent parents from allowing their children to be treated with medication if necessary.

Lead author Robert Hasty of Campbell University said, while many of the mistakes were relatively minor, some “could have clinical implications”. He urged fellow doctors to get involved in editing Wikipedia entries to improve their accuracy.

“Wikipedia is not about truth but about verifiability”

Reported by the BBC, James Heilman president at Wiki Project Med Foundation said he disagreed with the findings, “The conclusions of Hasty’s paper are not supported by the data he provides.

“One example he raises of a so called ‘error’ is Wikipedia’s recommendation around the diagnosis of blood pressure. We stated that three measurements are usually required.

“So does the National Institute for Health and Care Excellence in the UK which was our reference. Wikipedia is not about truth but about verifiability.”

The levels of air pollution in many of the world’s cities fail to meet the World Health Organisation’s safe guidelines, according to the urban air quality database. Air pollution which exceeds recommended guidelines puts people at risk of respiratory disease and other health problems.

According to the report, issued this week, only 12 percent of people living in the cities which measure air pollution are breathing air which meets the quality guidelines. About half of the urban population being monitored by WHO is exposed to urban air pollution which exceeds the recommended levels by at least 2.5 times.

WHO’s urban air quality database covers 1,600 cities across 91 countries – 500 more cities than the previous database (2011), revealing that more cities worldwide are monitoring outdoor air quality, reflecting growing recognition of air pollution’s health risks.

In cities where there is sufficient data to compare pollution levels today with those from previous years the situation is getting worse. WHO attributes this to many factors, but highlights fossil fuel use, dependence on private transport, insufficient energy use in buildings, and the use of biomass for cooking and heating.

The countries with the highest annual mean levels of PM2.5 (fine particles with a diameter of less than 2.5 micrometres) are Pakistan, Qatar, Afghanistan, Bangladesh, and Iran. However, half the 20 cities in the world with the highest PM2.5 levels are found in India. Delhi has the highest levels, 153 micrograms per cubic metre (ug/m3), in the world. This is six times the WHO “safe” level of 25 ug/m3.

Surprisingly, no Chinese cities ranked in the top 20 worst cities. Beijing, often in the news for its bad air quality, reported 56 ug/m3 and Chinese politicians have this year declared a “war upon pollution” write expathealth.org

In April 2014 WHO estimated that outdoor pollution was responsible for the deaths of some 3.7 million people under the age of 60 in 2012. The Organisation also highlighted outdoor and indoor air pollution as one of the biggest combined health risks worldwide.

The report notes that individual cities can take local action to improve air quality and thus go against regional trends. And good air quality can go hand in hand with economic development, as indicated by some major cities in Latin America which meet, or approach, the WHO air quality guidelines.