Eleanor Ho Boston University Statehouse Program BOSTON — As temperatures fall and positive coronavirus cases rise, advocates are concerned about homelessness in Massachusetts, where shelters remain at a reduced capacity due to the pandemic, and many are anticipating having to turn people away as outside conditions worsen. Estimates of the size of the Massachusetts homeless population hovers around the 18,000 mark, according to estimates from a 2019 report by the U.S. Department of Housing and Urban Development. Though in previous years Boston has been able to accommodate almost its entire homeless population, organizations are struggling to allow guests to distance and still provide adequate shelter.