26 juni, 2017

Doctors confirm thyroid cancer is increasing rapidly in Sweden

kvinna_smartmobil_thyroidA new scientific article from leading Swedish epidemiologist and oncologist Lennart Hardell’s research team confirms that there is a substantial increase in patients diagnosed with thyroid cancer during recent years in Sweden as well as in other Nordic countries. The increase has coincided with the growing use of so called ”smart phones”. These popular phones expose the radiation sensitive thyroid gland to high radiation due to the antenna’s placement at the lower part of the device. Another possible factor behind the increase is increased use of computed tomography in health care.

The researchers examined cases of thyroid cancer reported to the Swedish Cancer Registry in Sweden between 1970 and 2013. Their scientific article published in BMC Cancer in July 2016 notes that the radiation sensitive type of thyroid cancer (papillary) in particular is increasing among both women and men.

Women 20-39 years

In recent years there has been a break of the trend with a much more pronounced yearly increase in thyroid cancer incidence. A particularly alarming increase is seen among women aged 20-39 years (see the chart below of the number of cases per 100 000 inhabitants). In 2008, Apple introduced iPhone in Sweden that quickly became very popular.

hardell_thyroid_20-39

The incidence is also increasing in other Nordic countries, as indicated by the graph below showing the increase among women per 100 000 inhabitants for all ages.

hardell_thyroid_nordig_fig7

Thyroid cancers in USA

In the US, a study has shown that the number of cases of radiation-sensitive papillary thyroid cancer increased between 2002 and 2012 by 174%. The increase is also observed among the larger tumors (over 4 cm). Recent statistics show that between 2009 and 2014 only, the number of new patients with thyroid cancer in the United States increased from 37000 to 63 000. [1]

Particularly high increase has been reported in South Korea where the incidence per 100 000 inhabitants has reached 107 in 2008-2010. There is an ongoing discussion that the increase is due to increased screening. A recent article from scientists at the IARC also highlighted this possibility, however the IARC article only analysed  incidence until 2007. Furthermore the authors were not aware of the increasing factor in the environment that might contribute to the increase: radiofrequency radiation. Although it was classified by IARC in 2011 as ”possibly carcinogenic to humans”. The authors claim:

”There is no evidence of new risk factors or increased exposure to known contributors to thyroid cancer that might explain these steep upward trends”.

On the contrary radiofrequency exposure has exploded during the last decades and exposure to ionizing radiation has increased.

– In Sweden we have no screening of thyroid cancer that could explain the increase, says Dr Lennart Hardell.

Ionizing radiation risk

Ionizing radiation is an established risk factor for thyroid cancer. Thyroid cancer can occur in as little as 1 year after the exposure of children and 2.5 years after exposure of adults. Almost all thyroid cancer cases among children around Fukushima after the disaster in 2011 were the papillary sensitized variant. Radiation produces higher risk of thyroid cancer in children compared to adults while women are at higher risk compared to men.

The Swedish scientists also point to the increasing prevalence of radiographic examinations, mainly CT scans, in medical treatment as a possible contributing factor to the development. Between 1993 and 2010 the number of patients per year examined with CT increased from 40 per 1000 inhabitants to over 100 per 1,000 inhabitants. Between 2006 and 2013 the number of PET-CT examinations furthermore increased threefold.

Mobile phone radiation risk factor

Human exposure to radio frequency radiation from wireless technologies has increased tremendously since the start of this millennium.

Both regarding the use of mobile phones and the whole-body exposure from more distant sources, the thyroid is among the body’s most exposed parts. Given the fact that an antenna in recent years has been placed in the lower part of the so-called ”smart phones”, the exposure of the neck area has increased substantially, as illustrated by the image below. It shows the different mobile phone models since the 1990s: the first with external antenna at the top, then the built-in antenna in the upper part and in recent years with the internal antenna in the lower part.

hardell_thyroid_fig10

The Swedish scientists conclude that ”smart phones” have become very popular and the sale and consumption has increased dramatically in recent years. 3G and 4G have become the new standard for mobile phone communications.

3G promotes tumor growth and damage to DNA

3G has been shown to be able to damage the DNA of cells and promote tumor growth at levels that are around 50 times lower  (0.04-0.05 W / kg)  than the standard for mobile phones i.e. 2 W/kg. The standard however explicitly excludes protection against cancer hazards and covers only acute effects due to heating.

The so called ”smart phones” expose the user to more radiofrequency radiation. They can be connected to multiple networks and have built-in communication protocols for 2G, 3G and 4G, WiFi and Bluetooth.

Dr. Lennart Hardell and his co-authors suggest that previous research has shown that radiofrequency radiation (2.45 GHz) at levels below current limits causes effects on the thyroid. In one study, whole body exposure to 900 MHz (GSM) has been shown to cause cell changes in the thyroid gland in animals. Other studies have shown carcinogenic effects on the thyroid gland and disruption of the production of thyroid hormones.

– Our results clearly show that it is mainly the radiation sensitive type (papillary) of thyroid cancer that is increasing, writes the medical and research team. The conclusion is that both ionizing and non-ionizing radiation should be investigated as the underlying cause.

Pioneer on cancer risks from dioxin and PCBs

Dr Lennart Hardell has performed research on cancer risks with different environmental factors since the 1970s and was, for instance, among the first to show an increased cancer risk among people exposed to dioxin and among early users of mobile phones.

After his first studies linking dioxin exposure to cancer among workers in the 1970’s, dioxin was decades later fully recognized as carcinogenic to humans when the International Research on Cancer IARC classified dioxin (TCDD) as a Group 1 carcinogen in 1997. Dr Lennart Hardell has also shown that PCBs and glyphosate increase the risk of cancer. These factors are today classified by the IARC as possibly to fully admitted carcinogens. Dr Lennart Hardell was one of the 29 leading international experts invited by the IARC that assessed the cancer risks of mobile phones  in 2011. His research has been recognized as the most reliable in the field by the Supreme Court in Italy in an occupational injury case in 2012 (se also Microwave News article on the Italian case).