Straw Hair from Chlorine
Repeated and prolonged exposure to chlorine produces straw-like hair because of an oxidative or chemical burn (link). Proteins in the hair are damaged repeatedly, due to breakage in the disulfide and peptide bonds ( Robins, C.R., 2002; link). The end result is severe drying and straw texture.
Extreme damage to the hair cuticle causes bird-nesting, because it stands up like barbed-wire, producing knots and severe tangling.