In November, Darcy Padilla, a San Francisco-based documentary photographer, was awarded the 2010 W Eugene Smith award in humanistic photography. The award, which includes a $30,000 grant, is bestowed annually on a photographer who upholds the tradition of what the judges describe as Smith's "concerned photography and dedicated passion". Padilla certainly fits the bill.  She began the Julie Project 18 years ago, in 1993. Through thousands of pictures, as well as letters, journal entries, logs of phone conversations and newspaper cuttings, it tracks the blighted life of Julie Baird, a women Padilla first met in 1993 in the lobby of San Francisco's run-down Ambassador hotel – "barefoot, pants unzipped, and an eight-day-old infant in her arms". Back then, Julie was 18, and lived with a man called Jack, from whom she had contracted Aids. She was strung out on heroin, and had been living on the streets since running away from home at 14.  "For the last 18 years", Padilla writes on her website, "I have photographed Julie Baird's complex story of multiple homes, Aids, drug abuse, abusive relationships, poverty, births, deaths, loss and reunion. Following Julie from the backstreets of San Francisco to the backwoods of Alaska."  Padilla has undertaken other long-term projects, including a year spent documenting inmates with Aids in an isolation ward of maximum security prison in California, but Julie's story – her life story, in effect – has been the photographer's abiding preoccupation. She gave up an internship at the New York Times in her early twenties to devote her time to documentary photography, a vocation she initially funded by waitressing, bar jobs and the writing of countless grant applications. What drives Padilla is her urge to explore the myriad interconnecting social issues that bedevil the lives of what she describes as America's "the permanent poor".  Speaking to the Huffington Post after getting the award, Padilla said that Julie "was not that unusual"; was, in fact, just one of countless lives that begin badly and slowly, inexorably, become worse. "Julie was witty and smart, and she might just have grown up to be a teacher, but her mother was an alcoholic and her stepfather abused her, and she ended up on the streets at age 14."  In her detailed, fly-on-the-wall chronicling of Baird's unraveling life, Padilla shines a stark light on the relentless, grinding nature of urban poverty. She also offers us a poignant, sometimes brutally graphic, record of a life lived on the very margins of American society. Her camera follows Julie though her break-up with Jack, her struggle to get clean and stay off drugs, two more relationships, the birth of another five children, a spell in jail and her eventual relocation to Alaska, where she finally received hospice care. Padilla was there with her camera when Julie died in September of last year.  On Padilla's website, you can see the Julie Project in its entirety, alongside a moving film which ends heartbreakingly with what seems to be the sound of Julie's last breaths. Back in 1993, when she began telling Julie's story, Padilla saw the project as a latter-day take on W Eugene Smith's seminal photographic essay, Country Doctor, originally published in Life Magazine in 1948. It is a much more ambitious, detailed and, indeed, brave undertaking than that, and one that may disturb as much as it touches you. Many of the images of Julie's relentlessly messy life and her final struggle with Aids are harrowing, some might say intrusive. But, Padilla had Julie's blessing throughout and the two developed a deep friendship. There is tenderness, too, in the black and white photographs and the accompanying writings, as well as an unflinching eye for the telling detail.  The Julie Project would undoubtedly have earned Padilla the blessing of Smith, one of the great – and hardest to work with – idealists of documentary photography. Likewise, Padilla's decision to search out Baird's children, given up for adoption, in order to tell them their mother's story. (One child made contact with Julie just before she died, after his foster mother discovered Padilla's project online.) She is also trying to raise money towards the children's education. "Photography is a small voice, at best," Smith once said, "but sometimes one photograph can lure our sense of awareness". That is an unfashionable attitude today, but Padilla's extraordinary photo essay shows that this small voice still resonates.  Over 200 previously unseen photographs by the Russian master of constructivism, Alexander Rodchenko, are on display at the Art Sensus gallery in London as part of an intriguing group show, Rodchenko and His Circle. His subjects include mass parades, political meetings and sporting events, as well as the more familiar buildings he shot, often from dramatic angles, and his portraits of friends and fellow artists. A revolutionary photographer who never lost his painter's eye, or abandoned his constructivist vision.
Sean O'Hagan: Darcy Padilla's award-winning 18-year project documents the life and death of one woman, capturing in miniature the plight of America's 'permanent poor'