There are several hypotheses that are suspected but yet to be proven. One of the examples is the influence of electric wave to the human body.
Indian Council of Medical Research (ICMR) said that there is no evidence to prove that radiations from a mobile phone or towers have adverse effects on human health.
The Time of India: No conclusive proof of mobile radiations causing cancer: ICMR study
It looks a relieving report. However, the researchers are quite deliberate to declare the safety of electric waves. It is recommended to conduct further studies to gather more evidence.
Repeatedly I said, a prospective cohort study with a well-balanced, ideally randomized, large sample size, is needed to identify the causal relationship in an exact matter. But, it is unfeasible in terms of both financial and ethical aspects. For this reason, researchers of the environmental issues have to rely on alternative ways of study; case-control study, animal experiment, and inter-regional comparison, each of them has some shortcomings.
I think that the influence of electromagnetic waves in daily life is within a negligible level. At least, we cannot detect the harm of them with statistical significance. Most diseases such as cancers, strokes, and mental disorders emerge under the influence of a mixture of several factors. Taking many vegetables may be more beneficial than dropping a cell phone to prevent colon cancer.
Nonetheless, there are a couple of points to be noted. First, general principles are not applicable to extreme cases. There are a few people who are vulnerable to a certain type of electricity. I read some case reports. To be honest, most patients who claim they so are not so. But it is possible that a few people have such a special constitution.
Radiation level is another issue. Even if daily use of cell phone is harmless, it does not mean the safety of living near to the electric tower. It depends on the magnetic power and the distance from the place. The environment close to the tower should be cautiously observed.
Modern science lets us live comfortably. At the same time, the long-term influence of such technology is yet unknown in many areas. I am not pessimistic about this matter, continuous gathering of data is needed, nonetheless.