Evidence map›Paper›PMID 42819824›Full record

ArticleRSC advances2026

Spatial patterns and associations between microplastics and heavy metals in wastewater effluents of Pakistan's twin cities: insights from structural equation modeling.

Nayab Khan, Yue Geng, Najm Us Saqib, Mazhar Iqbal Zafar, Sohail Yousaf, Abida Farooqi, Zaib Jahan, Mohamed Hamza El-Saeid

Abstract read
In one paragraph

Article in RSC advances, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

8 authors.

Nayab KhanDepartment of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad 45320 Pakistan mzafar@qau.edu.pk nayab.khan4702@gmail.com syousaf@qau.edu.pk afarooqi@qau.edu.pk +92-5190644182.
Yue GengAgro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs Tianjin P. R. China gengyue@caas.cn.ORCID https://orcid.org/0000-0001-7097-9689
Najm Us SaqibDepartment of Chemistry, Faculty of Natural Sciences, University of Buner Khyber Pakhtunkhwa 19290 Pakistan najm_saqib@yahoo.com.ORCID https://orcid.org/0000-0002-0604-3584
Mazhar Iqbal ZafarDepartment of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad 45320 Pakistan mzafar@qau.edu.pk nayab.khan4702@gmail.com syousaf@qau.edu.pk afarooqi@qau.edu.pk +92-5190644182.ORCID https://orcid.org/0000-0001-7660-9283
Sohail YousafDepartment of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad 45320 Pakistan mzafar@qau.edu.pk nayab.khan4702@gmail.com syousaf@qau.edu.pk afarooqi@qau.edu.pk +92-5190644182.
Abida FarooqiDepartment of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University Islamabad 45320 Pakistan mzafar@qau.edu.pk nayab.khan4702@gmail.com syousaf@qau.edu.pk afarooqi@qau.edu.pk +92-5190644182.
Zaib JahanDepartment of Chemical Engineering, College of Engineering, Prince Mohammad Bin Fahd University Al-Khobar Saudi Arabia zjahan@pmu.edu.sa.
Mohamed Hamza El-SaeidChromatographic Analysis Unit, Department of Soil Sciences, College of Food and Agriculture Sciences, King Saud University 2460 Riyadh 11451 Saudi Arabia elsaeidm@ksu.edu.sa.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Microplastics (MPs) have become ubiquitous environmental pollutants. Wastewater treatment plants (WWTPs), which have been considered barriers to contamination, are now being understood as significant pathways for releasing MPs and heavy metals (HMs) in aquatic systems. The study has investigated the presence, nature, and association between MPs and HMs in effluents of twelve urban and industrial WWTPs in the twin cities of Pakistan. Microscopic studies were used to quantify MPs and characterize their size, shape, and color, while polymer identification was done by FTIR analyses based on characteristic functional groups. HM (Cu, Pb, Cd, Zn, Fe, and Mn) concentrations were analyzed by Atomic Absorption Spectroscopy (AAS). Pollution Load Index (PLI) and Ecological Risk Index (RI) were estimated to assess the possibility of environmental risks. Moreover, Partial Least Squares Structural Equation Modeling (PLS-SEM) was used to explain connections between MP size fractions, types of polymers, HM association, and ecological risk indicators. The outcome showed that MP contamination was prevalent in all WWTP effluents, with concentrations ranging from 477 to 1354 MPs per L. Small-sized microplastics (<300 µm), which were primarily fragments and fibers, dominated the MP assemblage. The polymers that were identified were PE, PP, PET, PS, PVC, nylon, and cellulose. Despite the relatively low ecological risk (6.67-36.13) associated with the overall HM pollution levels, considerable amounts of MP-HM association were reported. Polymers, particularly PVC and PE, exhibited strong statistical associations with Cd site concentrations, highlighting clear field co-occurrence trends between specific polymer profiles and target heavy metals. These exploratory co-variation pathways underscore the utility of multi-variate modeling in identifying structural distribution patterns within complex wastewater environments, thereby presenting microplastics as potentially significant co-occurring environmental vectors. Ultimately, these results underscore the need for polymer-focused wastewater management strategies to mitigate downstream ecological risks.

Identifiers

PMID42819824
PMCPMC13625055

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