**Abstract**

Physicochemical interaction with micro plastic at River Delimi represents one of the most pressing threats to water and plant resources as it is a challenge to human health. Micro plastics in the food chain constitutes a major threat to water, soil and plants which affect food safety, it affects public health when consuming products that have this pollutant, such as fruits, and vegetables. Micro plastics (MPs) are tiny particles broken down from larger pieces of plastics, accumulated in River Delimi. This study aimed at assessing the physicochemical parameters (Cd, Zn, Co, Pb and Ni) in water and (Ba, Ce, Rb, La, Nd, Ta, Sm, Sc and Th) while mercury and silver show high concentration (Hg, Ag) plants as it interaction with micro plastics (majorly polyethylene terephthalate (PET) concentration and plasticized polyvinylchloride (PVC both dry and rainy season)in the study area, along Rivers Delimi in Jos North LGA of Plateau State. Water and plant samples were collected from six (6) different irrigation sites in the area, namely Delimi village, Delimi area, Marhaba Masjd, Malam Adamu and Tudun Wada along the River Delimi, Barakin Kogi, and Baraki Naraguta along River Bonga, contain micro particles in edible plants due to the contamination of water-irrigated soils and methods to determine them. The negative effect of micro plastics on various food products and their interaction with physicochemical properties especially heavy metals impact on the environment is determined. Samples were analyzed to determine the concentration of the physicochemical parameters using the Atomic Absorption Spectrometer. Micro plastic are carriers for physicochemical parameters and exhibit diverse interactive effects, these interactions are poorly understood especially how they pose risks on living organisms. The challenges of their combined toxic effects and the potential hazards to human health were also discussed. Results show that the concentration of the physicochemical parameters in water as electrical conductivity, hydrocabonate, chloride, sodium carcium, chromium and lead while plasticized polyvinylchloride (PVC) both dry and rainy season, in river Delimi and river Bonga were pronounce. In plants potassium, phosphorus, molybdenum, manganese, mercury and silver were also high.

**Keywords:** micro plastics, heavy metals, interactions, microbe, aquatic environment

## **1. Introduction**

#### **1.1 Micro plastics**

Additives increase specific properties of plastic polymers; those called butyl tins stabilize polyvinyl chloride polymers (butyl tins)are found also in animal and human livers due to diet uptake [1]. Plastic items, which can be of different polymers or shape, can be classified according to size, and in particular, items ranging within 1 μm and 5 mm are called micro plastics (MPs) [2, 3]. Micro plastics (MPs) are small pieces of plastic, less than 5 mm (0.2inch) in length, that occur in the environments resulting to plastic pollution., Physicochemical factors accelerate the degradation time of plastics by mechanical stimuli, biological, thermal, and photo-oxidative degradation [4]. Micro plastic are varied contaminant suite originated from different product types, composed of various polymers and chemical additives, characterized by a broad range of colors and shape [5].

Micro plastic consist of carbon and hydrogen atoms bond together in polymer chain, other chemicals such as phthalates, polybrominated diphenyleither's (PBDEs) and tetrabromobisphenol A (TBBPA), are present in micro plastic and many of these chemical additive leach out of the plastic after entering the river**.** They are divided into primary or secondary, according to their origin. Primary micro plastic (fMPs) are the final products of industrial activities used in cosmetic [6].

Primary micro plastic: include micro bends (personal care products), plastic pellets (used in manufacturing), and plastic fibers (used in synthetic textiles or nylon). Secondary micro plastics (sMPs) are products of plastics litter/degradation. Exposure of plastic waste in the environment causes deterioration in its mechanical and physicochemical properties, leading to the formation of plastic fragments, which are considered as micro plastics (MPs) when their size is less than (<5 mm). Delimi river is an important natural drainage and irrigation system, ensuring water flows through is of paramount important, as the cultivation of vegetable crops in Jos, depend on it. The presence of micro plastic in River Delimi is a health risk. The primary challenges of MPs to ecosystems are their ubiquity and bioavailability for ingestion, entanglement or inhalation [7]. MPs can be accumulated in the environment due to their inert nature [8]. They have been found in table salts and potable water [9]. The health implications of MPs may be physical by blocking the digestive system due to particle localization, chemical with associated toxic chemical effects and biological involving toxins [10]. The exposure of aquatic organisms to MPs has been associated with short- and longterm adverse effects on organism's health, including biological feeding, reproduction, antioxidant defense and innate immunity [11–14]. A contaminant that is widespread in the environment, heavy metals can enter water bodies continuously due to their non-degradable nature and are recycled and enriched in the aqueous environment. MPs and heavy metals are not only acting as persistent pollutants, their combined pollution poses a new threat to the world. Due to the large surface area, MPs can act like magnets for toxic pollutants and concentrate them to a very high level [15, 16]. The need to reduce the amount or quantity of plastic waste emitted to safeguard environmental and human health is a task to be involved every stakeholder in the environment. Heavy metals are present in the environment from both naturally occurring and anthropogenic sources. As a contaminant that is widespread in the environment, Aquatic ecosystems contain a great diversity of microorganisms, which play critical roles in many biogeochemical processes. Their existence makes the interaction between MPs and heavy metals more complicated [16]. There is no existing

baseline study concerning the micro plastic challenges of River Delimi in Jos Plateau hence this study seek to provide the baseline.

#### **1.2 The chemical composition of micro plastics**

Aquatic ecosystems contain a great diversity of microorganisms, which play critical roles in many biogeochemical processes. Their existence makes the interaction between MPs and heavy metals more complicated. MPs provide an emergent ecological niche for microorganisms by the formation of microbial biofilms, named plastisphere [17, 18]. Primary micro plastics are intentionally manufactured in small sizes for different industrial purposes, such as housing and transportation applications and are generally made of polyethylene or polystyrene [19–21].

#### **1.3 The boundaries of the study**

The general aim of this study is to investigate the interaction between micro plastic and physicochemical parameters with challenges of micro plastic in River Delimi, Plateau State, Nigeria. River Delimi is within urban and commercial centre of Jos Plateau State capital, the investigated areas include; Delimi village, Delimi area, Congo Road, Tudun Wada, Anguwan Rogo, and BarakinNaraguta.

## **2. Materials and methods**

#### **2.1 Study area**

Rive Delimi covers a distance of about 15 km as it passes through Jos metropolis. It originates from Delimi village moves through Delimi area, Anguwan Rogo, Yelwan Mista Bow, Toro Bauchi, meeting up with the Rafin Zaki and extending to the Hadeja/ Jamaare River Basin and Lake Chard. It shares a boundary to the North with Toro Local Government Area of Bauchi State; to the South with Jos-South Local Government area; to the North-East with Jos-East Local Government Area; and to the West with Bassa Local Government Area [22]. Jos enjoys a temperate climate with average temperatures of between 280C (81.70F) maximum and 110C (51.70F) minimum. It covers a total land area of 291 km<sup>2</sup> (112 sq mi) with a 2006 census of 429,300 people. The warmest temperatures usually occur in the dry season months of March and April Jos is characterized by a mean annual rainfall of between 1317.5 mm (131.75 cm) and 1460.00 mm (146.0 cm), mostly from May to August The Onset and Cessation of rainfall in Jos are experienced in April (15 days in April), and October (15 days in October). The relative humidity is characterized by a marked seasonal variation [23]. The Jos Plateau is a high land region in North Central Nigeria. River Delimi is the major drainage system in Jos Metropolis. The river serves as a source of water for domestic use, fishing and irrigation. The River Delimi in Jos Plateau is the source of many Rivers in northern Nigeria including the Kaduna Gongola, Hadejia and Yobe River [23].

Plates 1, 2 and 3, show the type of menace that the disposal of solid wastes in water resources with cumulative effect micro plastic challenges which affect the water of the urban centers and the health hazards to the people who are exposed. The waste collection containers that were seen to be available at most locations in Jos are no longer in place at most of these locations.

#### **2.2 Data collection**

#### *2.2.1 Sampling methods and analysis*

Water samples were collected from 6 different sampling points marked WT1-WT6 (plate 1–3). Bulk water sampling, which facilitates sampling of smaller micro plastics but it, is limited by the size of the area.. The collection of samples from surface water was done using bulk water technique. Temperature, electrical conductivity (EC) and total dissolved solute (TDS) were measured in-situ during the sampling process. Water samples were filtered through Millipore filter paper of reweighed 0.45 μm pore size. The filtered water samples were acidified with 0.2%(v/v) concentration HN03 and kept in glass bottles. For anions analysis the sample were not acidify and titration carried out to ascertain the concentrations of the Anions. The filter papers containing the suspended solids were air-dried and reweighd. They were digested with 4/I (v/v) HN03/HCl mixture using a microwave device. After cooling, digestions were diluted to 30 ml with mili-Q water. At each of the sampling stations three samples of plants were collected close to water sampling station while water were collected using 1 liter polyethylene bottles with screw caps which were acid washed and rinsed with distilled water prior to the sampling... A total of 16 samples comprising of different types of plants alongside water samples each from the six sites along River Delimi and River Bonga were taken for laboratory analysis (see **Tables 1** and **2**). Specimens were labeled and transported to the laboratory in temperature - controlled boxes for analysis. An ambient temperature of 28° was maintained during transportation. Samples were digested with aqua regia solutions 3/I (v/v) HCl/HNO3 in microwave device. After cooling, digestions were diluted to 30 ml with mili-Q water.

#### *2.2.2 Microplatics analysis*

The different instrumental methodologies for determining and quantifying micro plastics in different matrices such as water, fruits and vegetables (see **Table 1**). The


#### **Table 1.**

*Identification and quantification micro plastics in river Delimi water, fruits and vegetables.*

*Micro Plastic Challenges in River Delimi Due to Its Interaction with Physicochemical… DOI: http://dx.doi.org/10.5772/intechopen.107150*


#### **Table 2.**

*Concentration of physical parameters and anions in water from all the sampling sites.*

techniques are focused on a physical type (non-destructive) determination; the composition of the micro plastic of the polymer that was separated from the sample by different analytical procedures is visualized. Reagents for separating the micro plastics from the samples [3, 19, 24, 25] with a high concentration of organic matter, where their action is to destroy the organic matter and release the micro plastics from the matrix in order to later be separated by filtration processes [7, 26–30]. Mesoplastic (MEP,>5 mm) and coarse micro plastic (Cmp,>2 mm) were visually identified from sieving fractions using a stainless-steel bowl with an imprinted grid (1x1 cm grid size) and inspected under stereomicroscope. Large micro plastics (L-Mp,>1 mm) and medium micro plastics (M-Mp,>0.3 mm) were analyzed after density separation micro plastics ZnCl2 and NaI. Separating micro plastics from water samples was done either by direct filtration [7, 31, 32] or organic materials such as dried leaves which showed recovery rate of 82% [33]. For density separation, solution of chemicals such as NaCl, NaI, NaCl, and ZnCl2 are used. After density separation, sieving, and filtration of floating sample material [30, 34]. Stained filters were visually detected under a stereomicroscope. Concentrated samples retained on the filters were identified and quantified. In the identification and quantification of micro plastics in samples, light microscopes have been applied in studies conducted in laboratories. Final identification of each potential plastics particle within the MEP, CMp, and L-Mp and M-Mp sizes was performed.

### **3. Results and discussion**

#### **3.1 Concentration of physical parameters (tem, pH, TDS and EC)**

**Figure 1** illustrates the concentration of Physical parameters in all sample locations. The highest concentrations of electrical conductivity (EC) are in sample locations WT1 (near Delimi street Bridge) along Delimi river and WT2 (katako) also along the Delimi river. Concentrations were lower in WT5-WT6 (AngwanRogo) (Naraguta) and along the Delimi, both along River Bonga.

The characteristic of physical parameters of samples from six samples that were analyzed for physical parameters in River Delimi (see **Table 2**).

**Figure 1.** *Concentration of physical parameters in water from the entire sampling site.*

Variation of physical parameters in River Delimi showed EC has highest concentration at WT1-WT2. Value of electrical conductivity EC of the water sample at WT1 (435 ohm/m), while WT5 exhibits lowest value of EC (210 ohm/m). Temperatures, pH and TDS have lower values (presented in **Figure 1**).

#### **3.2 Concentration of anions (S04<sup>2</sup>, Cland HC03)**

The concentration of Anions in water from all sample location. The concentration of hydrocarbon ate was high in sample WT2 –WT6 (Congo) along river Bonga and chloride at sample and WT5 –WT6 (Anguwan Soya) along river Bonga. However, the lowest concentration was recorded at sample station WT1 (Delimi street Bridge) for hydrocarbon ate and WT4 (Anguwan Rogo) for chloride.

The highest (see **Table 2** and presented in **Figure 2**) concentration of hydrocarbonate 98.98 (WT2) while the lowest concentration 38.38 (WT1), chloride highest concentration 99.26 (WT5) while the lowest concentration 28.36 (WT4) and sulfite which the least,highest concentration 35.5 (WT2) while lowest concentrations 23.5 (WT1). Hydrocarbon ate and chloride has higher values in River Delimi.

**Figure 2.** *Concentration of anions in water from the entire sampling site.* *Micro Plastic Challenges in River Delimi Due to Its Interaction with Physicochemical… DOI: http://dx.doi.org/10.5772/intechopen.107150*


**Table 3.**

*Concentration of cations and heavy metals in water from all the sampling sites.*

#### **3.3 Concentration of cations (Na<sup>+</sup> , K<sup>+</sup> , Mg2+ and Ca2+)**

The concentration of cations in all sample locations. The concentration of **Sodium (Na+ ) and calcium (Ca2+)** are higher in the sample locations from WT1-WT6 both along river Delimi and Bonga. Highest (see **Table 3** and presented in **Figure 3**) concentration of sodium in river Delimi 18.50 (ST6) mg/l while the lowest 14.48 (WT6), calcium highest concentration 14.50 (WT2) while the lowest concentration 14.32 (WT6).

#### **3.4 Concentration of heavy metals (Cr, Ni, Pb and Fe)**

The concentration of heavy metals in all sample locations. The concentration of chromium is higher in all the sample locations from WT1-WT6 both along river Delimi and Bonga. Lead is higher in the sample locations WT4-WT6. **Figure 4**

**Figure 3.** *Concentration of cations in water from the entire sampling site.*

**Figure 4.** *Concentration of heavy metals in water from the entire sampling site.*

revealed high concentration of chromium 3.62 (WT1) and lowest value of 2.77 (WT6) while lead higher value 2.36 (WT1), least value 2.28(WT2) (see **Table 3** and presented in **Figure 4**).

Micro plastics in River Delimi.

Concentration o f micro plastics (MPs) in river Delimi both dry and rainy season were abundant in color and dominated by fibrous items. Polyethylene terephthalate (PET) concentration 22.65% and Plasticized polyvinylchloride (PVC) concentration 50% while others 27.55% (dry season). Polyethylene terephthalate (PET) concentration 18.20%(and Plasticized polyvinylchloride (Plasticized (PVC) concentration 80.50% while others 11.70% (rainy season) Plasticized polyvinylchloride (Plasticized (PVC) were the predominant accounting for 50% and 80.50% in both dry and rainy season (presented in **Figures 5** and **6**).

#### **3.5 Concentration of metals (Ca2+, Mg2+ and K+ )**

The concentration of potassium (K<sup>+</sup> ) in all sample locations. The concentration of potassium is higher in all the sample locations from WT1-WT16 both along river Delimi and Bonga (see **Tables 4** and **5** and presented in **Figure 7**).

**Figure 5.**

*Concentration of micro plastic in river Delimi water from the entire sampling site (dry season).*

*Micro Plastic Challenges in River Delimi Due to Its Interaction with Physicochemical… DOI: http://dx.doi.org/10.5772/intechopen.107150*

#### **Figure 6.**

*Concentration of micro plastics in river Delimi water from the entire sampling site (rainy season).*

#### **3.6 Concentration of nonmetals (S and P)**

The concentration of sculpture and phosphorus in PT4-PT16 sample locations. The concentration of sulfur and phosphorus in sample locations PT4-PT16 are higher both along river Delimi and Bonga (presented in **Figure 8**).

#### **3.7 Concentration of metals and nonmetals**

The concentration of metals and nonmetals in all sample locations. The concentration of metals is higher in all the sample locations from PT1-PT16 both along river Delimi and Bonga (Presented in **Figure 9**).

#### **3.8 Concentration of heavy metals (Mo, Cu, Pb and Zn)**

The concentration of heavy metals n all sample locations. The concentration of molybdenum is higher in all the sample locations from PT1-PT16 both along river Delimi and Bonga (see **Table 6** and presented in **Figure 10**).

#### **3.9 Concentration of heavy metals (Ni, Co, Mn, Cr, Ba, Ti and B)**

The concentration of heavy metals in all sample locations. The concentration of Mn is higher in all the sample locations from W T1-WT16 both along river Delimi and Bonga. The concentration of B, Ti and Ba also show high concentration (presented in **Figure 11**).

#### **3.10 Concentration of heavy metals (W, Sc, Tl, Se and Ga)**

The concentration of metals in all sample locations. The concentration of metals that are less than or equal to one in all the sample locations from WT1-WT16 both along river Delimi and Bonga..Ba, Ce, Rb, La, Nd, Ta, Sm, Sc and Th were high (presented in **Figure 12**).

### **3.11 Interaction between MPs and heavy metals in plants irrigated with river Delimi water**

Micro plastics particles can interact with biological and synthetic systems due to their small size, enormous specific surface area, and high functionalization capacity,


#### **Table 4.**

*Concentration of metals and non metals in plants irrigated with river Delimi water from all the sampling sites.*

capable of even permeating biological membranes [3] Various sources of water and soils contaminated with micro plastics, are the source from where plants absorb water and nutrients.

The consumption of vegetable crops with a high level of heavy metals (Ba, Ce, Rb, La, Nd, Ta, Sm, Sc and Th) while mercury and silver show high concentration (Hg, Ag) (see **Tables 6** and **7**) due to high content of PVC in both dry and rainy season which is a challenge to humans. This showed that the use of water from river Delimi for irrigation may cause danger to the crops growing. Micro plastics increase cations of


*Micro Plastic Challenges in River Delimi Due to Its Interaction with Physicochemical… DOI: http://dx.doi.org/10.5772/intechopen.107150*

#### **Table 5.**

*Concentration of heavy metals in plants irrigated with river Delimi water from all the sampling sites.*

**Figure 7.** *Concentration of metals in plants irrigated with river Delimi water from the entire sampling site.*

Na<sup>+</sup> , Ca2+ and decrease K<sup>+</sup> , Mg2+, and Fe concentrations. Fragment, fiber shapes were identified in the surface water of the rivers, with fragment shape having the highest occurrence. The distribution of the plastics was as follows: polyethylene terephthalate (PET) – 22.65%, polyvinyl chloride (PVC) – 50%, others – 27.35% (Dry season), (PET) – 18.20%, polyvinyl chloride (PVC) – 80,50%, others – 11.70% (Rainy season) [35]. Estimated that humans are exposed to about 27 types of micro pollutants by consuming fruits and vegetables derived from irrigation water contaminated with

**Figure 8.** *Concentration of nonmetals in plants irrigated with river Delimi water from the entire sampling site.*

**Figure 9.**

these compounds [36], indicates that the concentration of micro plastics. Environmental factors may indirectly exert influence on MPs by changing biofilm structures on the MPs surface [10] found that nutrient salts, total nitrogen, total phosphorus, and pH have a greater influence on colony structure, while MP physical and chemical properties such as particle size and contact angle have less influence. Both MPs and heavy metals can accumulate at high level in the environment and consequently contaminate the food. Many studies have shown that MPs can absorb and release heavy metals, and their combined exposure may pose a potential threat to ecological system and human being [37].
