The content of heavy metals in the habitat of birds, Zeya-Bureya plain A.P. Pakusina, T.P. Platonova, S.A. Fokin, S.A. Lobarev and T.V. Gulenova E3S Web of Conf., 462 (2023) 03037 Published online: 12 December 2023 DOI: 10.1051/e3sconf/202346203037