Environmental Assessment and Monitoring of Heavy Metals in New York City Potable Water Systems: Case Study at Medgar Evers College, Correlation Analysis, and Public Health Impacts

Abstract

Reinforced by this study, New York City has one of the cleanest water systems in the world. Medgar Evers College (MEC) serves 7000 students/1050 faculty/staff. Given that: (1) students/faculty/staff spend 20–30% of their daily time there; (2) potable water sources must abide by the EPA’s maximum contamination levels (MCLs); and (3) a detrimental impact on human health arises from violations to EPA’s water quality mandates, we quantified the abundance of 27 heavy metals (96 samples, N = 3) using MEC as a case study. Water was collected from all potable water sources, following EPA protocols for sample-matrix preparation, collection, and wet-chemical analysis. Linear polyethylene containers/caps were used to prevent sample contamination while the water samples were spiked with HNO3 (aq) for preservation. Heavy metal concentrations were quantified using New Jersey’s Meadowlands Environmental Research Institute’s Inductively Coupled Plasma-Mass Spectrometer (ICP-MS, Agilent 7700X) in no gas, and He flow modes. Ninety-five percent of sample concentration relative standard deviations (RSDs) reveal four distinct regions: (1) where one mode is more precise than the other, and sample data exhibit very good to excellent precision, RSD ≤ 15%; (2) despite being at low concentrations, measurements exhibit good to excellent precision, RSD ≤ 20%; (3) species concentrations ≥0.1 ppb very good to excellent precision is shown, RSD ≤ 15%; and (4) species at concentrations ≤ 10−3 ppb display fair to very poor precision, RSD ≥ 30%. All heavy metals complied with their respective EPA MCLs (except Fe). Over 90% of Fe sample concentrations were enhanced by up to about 30×. Two samples exhibited [Pb] = 13.7 (No gas mode, RSD = 3.32%) and 14.8 ppb (He mode, RSD = 0.75%), which is close to the EPA Primary MCL, 15 ppb. Based on EPA/WHO end-member equations, we estimate a 1/103 to 1/108 chance of cancer attainment from long-term exposure to the range of concentrations of heavy metals measured in this study.