A link between increased ICP and altered sodium and water retention was suggested by a report in which 77% of IIH patients had evidence of peripheral edema and 80% with orthostatic retention of sodium and water. Impaired saline and water load excretions were noted in the upright position in IIH patients with orthostatic edema compared to lean and obese controls without IIH. However, the precise mechanisms linking orthostatic changes to IIH were not defined, and many IH patients do not have these sodium and water abnormalities. Astronauts are well known to have orthostatic intolerance upon reentry to gravity after long-duration spaceflight, and the dietary sodium on orbit is also known to be in excess of 5 grams per day in some cases. The Majority of the NASA cases did have high dietary sodium during their increment. The ISS program is working to decrease in-flight dietary sodium intake to less than 3 grams per day. Prepackaged foods for the International Space Station were originally high in sodium at 5300 mg/d. This amount has now been substantially reduced to 3000 mg/g as a result of NASA reformulation of over ninety foods as a conscious effort to reduce astronaut sodium intake.

While exercise is used to maintain muscle, bone and cardiac health during spaceflight, its effects on ICP and IOP have yet to be determined. The effects of resistive exercise on the development of ICP remains controversial. An early investigation showed that the brief intrathoractic pressure increase during a Valsalva maneuver resulted in an associated rise in ICP. Two other investigations using transcranial Doppler ultrasound techniques showed that resistive exercise without a Valsalva maneuver resulted in no change in peak systolic pressure or ICP. The effects of resistive exercise in IOP are less controversial. Several different studies have shown a significant increase in IOP during or immediately after resistive exercise.

There is much more information available regarding aerobic exercise and ICP. The only known study to examine ICP during aerobic exercise by invasive means showed that ICP decreased in patients with intracranial hypertension and those with normal ICP. They suggested that because aerobic exercise is generally done without Valsalva maneuvers, it is unlikely that ICP will increase during exercise. Other studies show global brain blood flow increases 20-30% during the transition from rest to moderate exercise.

More recent work has shown that an increase in exercise intensity up to 60% VOmax results in an increase in CBF, after which CBF decreases towards (and sometimes below) baseline values with increasing exercise intensity.

While radon presents the aforementioned risks in adults, exposure in children leads to a unique set of health hazards that are still being researched. The physical composition of children leads to faster rates of exposure through inhalation given that their respiratory rate is higher than that of adults, resulting in more gas exchange and more potential opportunities for radon to be inhaled. In addition to this potentially higher dose of radon inhalation, children have smaller lungs, which can become damaged much more quickly than adults’ lungs. For example, children who are exposed to radon and who live in a household where they are exposed to tobacco smoke have a 20 times greater risk of developing lung cancer.

The resulting health effects in children are similar to those of adults, predominantly including lung cancer and respiratory illnesses such as asthma, bronchitis, and pneumonia. While there have been numerous studies assessing the link between radon exposure and childhood leukemia, the results are largely varied. Many ecological studies show a positive association between radon exposure and childhood leukemia; however, most case control studies have produced a weak correlation. Genotoxicity has been noted in children exposed to high levels of radon, specifically a significant increase of frequency of aberrant cells was noted, as well as an “increase in the frequencies of single and double fragments, chromosome interchanges, [and] number of aberrations chromatid and chromosome type”.

UNSCEAR recommends a reference value of 9 nSv (Bq·h/m).

For example, a person living (7000 h/year) in a concentration of 40 Bq/m receives an effective dose of 1 mSv/year.

Studies of miners exposed to radon and its decay products provide a direct basis for assessing their lung cancer risk. The BEIR VI report, entitled "Health Effects of Exposure to Radon", reported an excess relative risk from exposure to radon that was equivalent to 1.8% per megabecquerel hours per cubic meter (MBq·h/m) (95% confidence interval: 0.3, 35) for miners with cumulative exposures below 30 MBq·h/m. Estimates of risk per unit exposure are 5.38×10 per WLM; 9.68×10/WLM for ever smokers; and 1.67×10 per WLM for never smokers.

According to the UNSCEAR modeling, based on these miner's studies, the excess relative risk from long-term residential exposure to radon at 100 Bq/m is considered to be about 0.16 (after correction for uncertainties in exposure assessment), with about a threefold factor of uncertainty higher or lower than that value.

In other words, the absence of ill effects (or even positive hormesis effects) at 100 Bq/m are compatible with the known data.

The ICPR 65 model follows the same approach, and estimates the relative lifelong risk probability of radon-induced cancer death to 1.23 × 10 per Bq/(m·year). This relative risk is a global indicator; the risk estimation is independent of sex, age, or smoking habit. Thus, if a smoker's chances of dying of lung cancer are 10 times that of a nonsmoker's, the relative risks for a given radon exposure will be the same according to that model, meaning that the absolute risk of a radon-generated cancer for a smoker is (implicitly) tenfold that of a nonsmoker.

The risk estimates correspond to a unit risk of approximately 3–6 × 10 per Bq/m, assuming a lifetime risk of lung cancer of 3%. This means that a person living in an average European dwelling with 50 Bq/m has a lifetime excess lung cancer risk of 1.5–3 × 10. Similarly, a person living in a dwelling with a high radon concentration of 1000 Bq/m has a lifetime excess lung cancer risk of 3–6%, implying a doubling of background lung cancer risk.

The BEIR VI model proposed by the National Academy of Sciences of the USA is more complex. It is a multiplicative model that estimates an excess risk per exposure unit. It takes into account age, elapsed time since exposure, and duration and length of exposure, and its parameters allow for taking smoking habits into account.

In the absence of other causes of death, the absolute risks of lung cancer by age 75 at usual radon concentrations of 0, 100, and 400 Bq/m would be about 0.4%, 0.5%, and 0.7%, respectively, for lifelong nonsmokers, and about 25 times greater (10%, 12%, and 16%) for cigarette smokers.

There is great uncertainty in applying risk estimates derived from studies in miners to the effects of residential radon, and direct estimates of the risks of residential radon are needed.

As with the miner data, the same confounding factor of other carcinogens such as dust applies. Radon concentration is high in poorly ventilated homes and buildings and such buildings tend to have poor air quality, larger concentrations of dust etc. BEIR VI did not consider that other carcinogens such as dust might be the cause of some or all of the lung cancers, thus omitting a possible spurious relationship.

Zhu Ling (, born 1973) is best known as the victim of an unsolved 1995 thallium poisoning case in Beijing, China. Her symptoms were posted to the Internet via a Usenet newsgroup by her friend from Peking University, Bei Zhicheng and were subsequently proven to be caused by thallium poisoning. Her case was then reviewed by physicians in many different countries who examined her symptoms and made suggestions as to diagnoses and treatment. This effort was recognized as the first large scale tele-medicine trial. Her life was ultimately saved, but she suffered serious neurological damage and permanent physical impairment.

This case drew great attention in the Chinese media, because the victim and the suspect were living in the same dormitory in the most prestigious university of China, and the case was never solved. Internet discussion of the crime has continued since then and became a hot topic on major online Chinese communities very frequently as a high-profile cold case.

In 1994, Zhu Ling was a sophomore in Class Wuhua2 (Class 2 majored in Physical Chemistry) at Tsinghua University in Beijing. Classmates described her as attractive, intelligent, and talented, with an interest in music. She began to show strange and debilitating symptoms at the end of 1994, when she reported experiencing acute stomach pain, along with extensive hair loss. Following her hospitalization at TongRen Hospital, her condition gradually improved and she was allowed to return to school. The following March, however, her old symptoms returned worse than before, this time accompanied by pain in her legs, loss of muscular eye control, and partial facial paralysis. Unable to breathe on her own, she was placed on a respirator.

One physician at Peking Union Medical College Hospital (PUMCH), Dr. Li Shun-wei, reported having diagnosed a similar poisoning case in the 1960s and strongly suspected that Zhu Ling's symptoms were caused by thallium poisoning. However, Zhu Ling denied that she had had any contact with thallium in class, a claim which was confirmed by her university's chemistry department. As a result, her doctors ruled out thallium poisoning as a potential cause. Instead, she was diagnosed with and treated for Guillain–Barré syndrome. Her condition deteriorated rapidly.