LOS ANGELES — Measuring radiation exposure using current Federal Communications Commission guidelines underestimates how much radiation most people receive from their cellphones, researchers said Monday in a study published in the journal Electromagnetic Biology and Medicine.

The authors of the study, including several members of Environmental Health Trust, a nonprofit devoted to identifying and controlling environmental health risks, pointed to several reasons why. One is that the current assessment bases evaluations of how much radiation people are exposed to from their phones on measurements taken using a quite large, liquid-filled plastic model of the adult human head (known as the Specific Anthropomorphic Mannequin, or SAM). Smaller people — 97 percent of the population, the authors wrote — will have higher proportional exposure. Children receive twice as much microwave radiation to the head from phones as adults, the study estimated, and 10 times the amount to bone marrow.

Also, current assessments don’t examine exposure to parts of the body other than the head, the study noted. Even when a phone is stowed away in a pocket, it continues emitting radiation.

The authors reviewed examples of research demonstrating negative effects of cellphone use, including recent epidemiological studies suggesting correlations between cellphone use and brain cancer.

The Electromagnetic Biology and Medicine paper called on the cellphone industry to stop using the SAM-based system to certify phones for use. A better method, the authors said, would be for industry to begin using the computer-based, “virtual family” simulation approach, which assesses the radiation absorption for 10 different-sized people: a 5-year-old girl, a 6-year-old boy, an 8-year old girl, an 11-year-old girl, a 14-year-old boy, a 26-year-old woman, a 35-year-old man, an obese man and three women at different stages of pregnancy.