Plastic and Bacterial Quality Assessment in Some Serchet and Bottle Water After Sunlight Exposure in Gwale Local Government Area

Abstract
The study was aimed to assess the microplastic, physicochemical and bacteriological quality of sachet and bottle water sold and consumed in Gwale local government area in Kano State. The physicochemical properties of the plastic bottled water after sunlight exposure are presented in Table 2, 3, 4 and 5. The pH value of water samples ranged from 6.40 to 7.18 (zero-week exposure), 6.11 to 7.13 (one week exposure), 6.75 to 8.22 (two weeks exposure), 5.57 to 6.80 (three week exposure) and 6.11 to 7.50 (four week exposure). The trend showed that the pH of the water samples decreased gradually with increasing exposure to sunlight. Generally, the pH levels recorded were falls withing the standard limit for drinking water (6.5 to 8.5) by WHO, SON and NIS, except for sample A on day zero. There was significant increment in TDS values from 0 week to week one, two, three- and fourth-weeks exposure to sunlight. The TDS values range from (14.03– 45.54 mg/l) for zero week, (5.50– 47.00 mg/l) for week one, (0.10–0.65 mg/l) for week two (0.14– 0.85 mg/l) for week three and (0.13 –0.85 mg/l) for week four. The Electrical Conductivity (EC) of the bottled water exposed to sunlight showed significant increase for all samples, ranging from (13.49 - 190.04 ms/cm) for 0 week exposure, (18.00 - 63.00 ms/cm) for week one exposure (0.19 - 0.61 ms/cm) for week two exposure (0.19 -0.73 ms/cm) for week three exposure and (0.23- 0.49 ms/cm) for week four exposure. This increase in EC may be occasioned by prolonged exposure to sunlight overtime, as the trend obtained was similar to the result obtained by Janan et al. (2013) and Muhammad et al. (2011) under similar conditions. The increase in EC and TDS which are interrelated also correlate with the increasing ions for other physicochemical parameters and heavy metal (zinc) with increase in sunlight exposure. The mean temperature values for day 0-week, week 1,2,3 and 4 ranged from (28.85– 31.95 oC), significant increase in temperature was recorded but the values were within the standard limits. By (WHO) as far as bacterial quality pathogenic, microorganism pose and obvious health risk to all consumers. HPC values where particularly high clearly indicating the lack of proper water treatment not only from main distribution supply system, but the improper functioning of the filters installed at the consumers end as well. Also, the presence of E. coli and the potentially lethal strain 0157:H7 is very distressing as it can cause severe disease in children.