Influence of human-induced pressures on dissolved and particulate metal concentrations in a South American estuary

LA COLLA, NOELIA S.; BOTTÉ, SANDRA E.; NEGRIN, VANESA L.; SERRA, ANALÍA V.; MARCOVECCHIO, JORGE E.

ENVIRONMENTAL MONITORING AND ASSESSMENT

SPRINGER

Lugar: Berlin; Año: 2018 vol. 190

0167-6369

Coastal areas are urbanized and industrializedenvironments, affected by dredging operations, dischargesof untreated municipal wastewaters, and farming. Developingcountries are in continuous growth and will deal, ina close future, with the highest rate of coastal transformation,posing serious risks for the ecological and environmentalvalue of ecosystem assets. This research aims tostudy the dissolved and particulate Cr, Ni, Pb and Znvalues within an argentinean estuarine environment whichis currently under human-induced pressures. Concentrationsof all the metals under analyses showed seasonalvariability of both dissolved and particulate metals. Animportant outcome of this study was that dissolved Cr, Pband Zn attained maximum values and overall increasedconcentrations with respect to previous records from thesame area. Indeed, the highest concentrations were foundduring the dredging operations or in association withincreases in the metal levels from wastewater discharges.The results also indicated that human activities contributedthe least to the dissolved Ni concentrations. The particulatefraction of Cr, Ni and Zn showed an upward trendin the concentrations, particularly during the last twosampling dates, being also positively correlated betweeneach other. Regarding their respective environmental qualitystandards,many samples achieved dissolved Cr and Znconcentrations above the maximum values recommendedby international guidelines. Thus, this study highlights thepossibility of stressors like dredging activities and municipalwastewaters to cause increases in the water columnpollution levels.