Metal(loid)s in tap-water from schools in central Bangladesh (Mirpur): Source apportionment, water quality, and health risks appraisals

Md Joynal Abedin; Rahat Khan; Md Abu Bakar Siddique; Abdul Hadi Al Nafi Khan; Md Tariqul Islam; Md Bazlar Rashid

doi:10.1016/j.heliyon.2023.e15747

Metal(loid)s in tap-water from schools in central Bangladesh (Mirpur): Source apportionment, water quality, and health risks appraisals

Heliyon. 2023 Apr 28;9(5):e15747. doi: 10.1016/j.heliyon.2023.e15747. eCollection 2023 May.

Authors

Md Joynal Abedin^{1

2}, Rahat Khan², Md Abu Bakar Siddique³, Abdul Hadi Al Nafi Khan², Md Tariqul Islam², Md Bazlar Rashid⁴

Affiliations

¹ Centre for Higher Studies and Research, Bangladesh University of Professionals (BUP), Mirpur Cantonment, Mirpur, Dhaka 1216, Bangladesh.
² Institute of Nuclear Science and Technology, Bangladesh Atomic Energy Commission, Savar, Dhaka 1349, Bangladesh.
³ Institute of National Analytical Research and Service (INARS), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhanmondi, Dhaka 1205, Bangladesh.
⁴ Geological Survey of Bangladesh, Segunbaghicha, Dhaka 1000, Bangladesh.

Abstract

Considering the health risks originating from the exposure of metal(loid)s in tap-water and the concomitant vulnerability of school-going students, 25 composite tap water samples from different schools and colleges of central Bangladesh (Mirpur, Dhaka) were analyzed by atomic absorption spectroscopic technique. Elemental abundances of Na, Mg, K, Ca, Cr, Mn, Fe, Co, Ni, Zn, As, Cd, and Pb in the studied tap water samples varied from 4520 to 62250, 2760-29580, 210-3000, 15780-78130, 1.54-5.32, 7.00-196, 2.00-450, 0.04-1.45, 8.23-24.4, 0.10-813, 0.10-10.5, 0.002-0.212, and 1.55-15.8 μgL^-1, respectively. Dissolved metal(loid)s' concentrations were mostly within the national and international threshold values with few exceptions which were also consistent with the entropy-based water quality assessment. Multivariate statistical approaches demonstrated that hydro-geochemical processes like water-rock interactions mostly govern the major elemental (Na, Mg, K, Ca) compositions in tap water. However, anthropogenic processes typically control the trace elemental compositions where supply pipeline scaling was identified as the major source. Cluster analysis on sampling sites separated two groups of schools and colleges depending on their establishment years where tap water from older schools and colleges possesses relatively higher levels of metal(loid)s. Hence, gradual pipeline scaling on a temporal scale augmented the metal(loid)s' concentrations in tap-water. In terms of non-carcinogenic health risks estimation, studied tap-water seems to be safe, whereas elemental abundances of Pb and As can cause carcinogenic risks to school-going people. However, progressive deterioration of water quality by pipeline scaling will be supposed to cause significant health risks in the future, for which preventative measures should be adopted.

Keywords: Health risks on exposure; Metal(loid)s load; Source apportionment; Supply pipe-line scaling; Tap water from educational institutes; Tap water quality.