a-b | c | d-f | g-j | k-m | n-p | r-s | t-z
NCI National Cancer Institute in the USA, which performed a major epidemiological study on EMFs published in 1997
NGC, NGT Historical references to National Grid Company, which in 2002 became part of National Grid Transco and then National Grid plc in July 2005. The company which operates the England and Wales high-voltage transmission network - now known as National Grid Electricity Transmission plc
NIEHS National Institute of Environmental Health Sciences, a USA government organisation
NRPB National Radiological Protection Board. Created by Act of Parliament to advise on radiation issues including EMFs. In 2004 became part of the Health Protection Agency (HPA).
Near field the situation where you are close to the source of the field. Electric and magnetic fields are not coupled to each other and radiation is small; the two fields exist separately. Nearly always the case at 50 Hz
Net current Created in a circuit when the live and neutral currents are not equal, usually because some of the neutral current has diverted out of the cable.
Odds Ratio The usual way of expressing the result of a case-control epidemiological study, often nearly the same as the relative risk or risk ratio. An odds ratio of 1 means there is no association between exposure and disease. Odds ratio greater than 1 mean the exposure is associated with the disease.
OMS the French version of WHO. Organisation Mondiale de la Sante
Phasing The way in which the two circuits of a power line are wired relative to each other, which affects the magnetic field produced
Pooled analysis An epidemiological analysis where the data from a number of individual studies are pooled to allow a single analysis to be made of the combined data set.
Possibly carcinogenic One of the categories used by IARC to classify agents. The middle of five categories, below “established” and “probably”.
Potential difference. The same thing as voltage. This term arises because the voltage is the potential to do work.
Power The rate at which work is done, measured in watts. In electrical circuits it is the product of voltage and current.
Power frequencies In the UK the frequency of the mains (and the rest of the electricity system) is 50 Hz. “Power frequencies” is often used to cover both 50 Hz and the first few harmonics.
Powerwatch A UK EMF interest group