ABSTRACT

Quarrying is an anthropogenic activity that involves the removal of soil to extract non-metal and nonfuel minerals from rock (and most times vegetation). This study aimed to determine the status of particulate matter (PM_2.5 and PM₁₀), elemental composition (Pb, Cd, As, Ni, Fe and Zn, Ca, Mg, K, Na, Mn and Co) and weather parameters (temperature and humidity) via sampling and analysis of samples from different locations at quarry site in Ebonyi State, Nigeria. The objectives of the study were: to determine the concentrations of the elemental compositions of granite, to assess the physicochemical properties of pond water at the quarry site, to assess the concentrations of heavy metals and macronutrients in soil, plants, and pond water at the quarry site, to determine the concentration of particulate matter around the vicinity of the quarry. Different sizes of chippings such as 0.50 unmixed, 0.50 mixed, 3/8 inch, 1/2 inch, 1 inch, hard-core, and dust were collected at five (5) different positions at the quarry site Three (3) large pond water in the South east P1 (SE), South west P2 (SW), and South central P3 (SC) directions of the China quarry site were selected for collection of water samples. Surface soil (0-15 cm) samples were collected at the distance of 1 m, 180 m, and 360 m in south east (SE), south central (SC) and southwest (SW) directions of the quarry site. Fresh leaves were sampled from different parts of four (4) plant species viz Crotolaria retusa, Boerhavia eracta, Pennisetum polystachion, and Paspalum scrobiculatum. All the samples were collected randomly in February 2019. The concentrations of Pb, Cd, As, Ni, Fe and Zn in soil, plant and water were determined using Atomic Absorption Spectrometer while macro-elements (Ca, Mg, K, Na, Mn and Co) and physicochemical parameters (pH, TA, TS, TDS, TSS, DO, COD, BOD and temperature) were analysed using standard methods. The highest concentration of Pb, Cd, As, Ni, Fe and Zn in soil was obtained at a distance of 1 m from the edge of the quarry.  The highest concentrations of Pb (2.00±0.05 mg/kg), Zn (6.85±0.06 mg/kg), Mn (94.21±0.13 mg/kg), Fe (3,461.65±3.61 mg/kg), Ca (5.41±0.01 %) and K (0.24±0.02 %) in different sizes of granites were recorded in dust particles. The highest temperature (45.88±0.53 °C) and relative humidity (49.05±0.21 %) was recorded close to the conveyor belt and walk way to pit, respectively.  The concentration of PM_2.5 (69.00±1.41 μg/m3) and PM10 (2,829.50±12.02 μg/m³) were highest at the chippings deposition cum collection point. The values of heavy metals in soil were below the Dutch criteria and permitted limits of WHO, except for Cd. Crotalaria retusa assimilated highest level of Pb (2.42±0.00 mg/kg), As (0.43±0.01 mg/kg) and Zn (5.52±0.00 mg/kg) while Cd (0.09±0.00 mg/kg), Ni (1.13±0.00 mg/kg) and Fe (54.70±0.00 mg/kg) were highest in Pennisetum polystachion. The values of Pb (0.60±0.00 to 2.42±0.00 mg/kg) and As (0.11±0.00 to 0.43±0.01 mg/kg) in plants was higher than the permissible limit of 0.30 mg/kg (Pb) and 0.2 mg/kg (As) established by WHO, thus posing a serious health risk to man and animals that depend on such plants for food and medicine. The concentrations of Cd (0.01±0.00 to 0.02±0.00 mg/l), Pb (6.70±0.78 to 7.87±1.08 mg/l), Ni (1.03±0.04 to 1.37±0.04 mg/l), As (1.99±0.02 to 2.35±0.09 mg/l), Fe (3.66±0.44 to 4.18±0.04 mg/l) and Zn (2.47±0.06 to 3.17±1.13 mg/l) were higher than the permissible limit of drinking water by World Health Organization, WHO. Also, the values of biochemical oxygen demand, BOD (37.57±1.44 to 53.13±0.86 mg/l), chemical oxygen demand, COD (59.55±0.51 to 61.28±0.64 mg/l), dissolved oxygen, DO (5.14±1.51 to 5.75±1.09 mg/l), Mn (3.64±0.91 to 5.10±1.27 %) and Ca (91.88±0.18 to 102.83±0.59 %) were higher than the permissible limit recommended by WHO. From the results, it is recommended that (i). people living around the quarry site should not be using the pond water for irrigation of crops; (ii). they should also avoid using the fodder and medicinal plants; (iii). and they should not use the farmland for crop production to avoid bio-magnification of heavy metals in animals including man.