Both women, who emigrated from the Soviet Union in the 1980s but recently returned to Russia for a vacation, were severely sickened, but their lives are not in danger, medical officials in Moscow said. “They have positive dynamics, and their condition is improving,” Dr. Viktor M. Kaznacheyev, the chief physician at the Sklifosovsky Clinic in Moscow, told The New York Times. The women had been treated at the clinic since falling ill Feb. 24. Their Moscow vacation reportedly began Feb. 14 and they were due back in California on Feb. 26. The poisoning has stunned friends and family back home. Oyuna Chuluun, a medical assistant at Marina Kovalevsky’s storefront clinic in West Hollywood, said she thought the apparent poisoning an accident. She said Marina was divorced. “We just don’t believe someone would want to poison her,” Chuluun told The Associated Press. Doctors say the mother and daughter were poisoned with thallium, a reputed poison of choice for intelligence agencies and assassins. It was initially suspected to be the toxin used in last year’s fatal poisoning in London of former Russian security agent Alexander Litvinenko, but it was later determined he had ingested the rare radioactive isotope polonium-210. Studio City neighbors of Marina Kovalevsky say she and her daughter moved into a home in the hills above Laurel Canyon around five years ago. Yana Kovalevsky later moved away, they said. They describe the sandy-haired doctor as a quiet woman seen each morning before her vacation walking her dog down the street from her tidy two-story, yellow home, which was recently remodeled. “It’s terrible,” said Robin Perud, 40, who lives across the street. Neighbor suspicious Lionel Kipnis, who lives next door and has picked up her mail for three weeks, figured something was wrong when they did not return. “A lady, a friend of theirs’, stopped by Saturday and said they’d fallen ill.” Marina Kovalevsky is an internal-medicine specialist in private practice in West Hollywood and has had admitting privileges at Cedars-Sinai Medical Center since 1999, a spokeswoman for the hospital said. She was educated in the 1970s in Kemerovo, an industrial and coal-mining region in southern Siberia. “She left Los Angeles in perfectly good health,” said Dr. Arkady Stern, a colleague covering for her at her West Hollywood practice on Santa Monica Boulevard. Thallium, an element with no taste or odor, has been used as an ingredient in insecticides and rat poison, and by criminals and intelligence services, including those of the former Soviet Union and of Iraq under Saddam Hussein. Slow-acting poison It was said to have been selected by the CIA as a poison to be sprinkled in Fidel Castro’s shoes – a plot that was never carried out. When ingested, it is a slow-acting poison that can cause excruciating abdominal pain, breathing difficulties, damage to the nervous system and extensive hair loss. Stern said the two women had been administered Prussian blue, an antidote commonly used to counteract thallium’s effect, and had undergone dialysis to help rid their systems of lingering toxins. There is no indication that either woman would have been of interest to Russian intelligence services, and no clear criminal motive for the poisoning. “My personal opinion,” Stern said, “is that it could be some mistake. I cannot imagine that anyone in their right mind would want to hurt this person. She is very loved and very respected by her patients, her colleagues and her friends.” Wire services contributed to this report. dana.bartholomew @dailynews.com (818) 713-3730 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! A Studio City doctor and her daughter who were mysteriously poisoned in Moscow with a highly toxic element popular with assassins returned to Los Angeles on Wednesday to waiting ambulances and a throng of reporters. Looking pale and unable to walk on their own, Dr. Marina Kovalevsky, 49, and her daughter, Yana, 26, were escorted through a crush of camera crews, reporters and bright flashes at the Tom Bradley International terminal. “We’ve just had a 13-hour flight. We’ll be more than happy to talk to you later,” Yana Kovalevsky told the media. “Just leave us alone, please. Have some respect, please. Get the camera out of our face.” The pair left the Aeroflot jet in airline wheelchairs and were helped by friends and family members into other wheelchairs. They were then placed in separate ambulances about 5:20 p.m. and presumably taken to an area hospital, although officials would not confirm where they were going.