 environmental issues and challenges confronting surface waters in south america a review 2021  environmental issues and challenges confronting surface waters in south america a review 2021 environmental issues and challenges confronting surface waters in south america a review 2021 authors timothy oyedotun nasrudeen ally link  https wwwsciencedirectcom science article pii s2667010021000287 webmaster wed 4052023 934 environmental issues and challenges confronting surface waters in south america a review 2021  faculty of earth and environmental sciences 