India's export of human hair to China is a booming business but it's also entangled in issues of respiratory disease and child labor...Despite previous allegations that it has relied on prison labor, [Henan Rebecca]...expects to open more retail outlets...in China...Dr Mahesh Umachadi, medical officer at Bhagyanagar's public health center, [said]...40 percent [of his patients] suffer from respiratory tract infections, which he attributes to tiny dust particles that are emitted during hair processing and settle in the lungs...The business already employs too many tiny hands...[I]t remains common to see small girls in pigtails bent over piles of hairballs.