Environmental and Health Risk Assessment of Particulate Matter Associated With Dusty Football Field

Over the decades there have been problems associated with Particulate Matter (PM) arising from anthropogenic activities. Evaluation and health risk assessment of PM associated with football field was carried out in 5 sampling locations, including the control station. Digital portable AEROCET 513 (Metone instrument) PM meter was used for the evaluation Results showed levels of PM for; PM1.0 (13.73 – 20.18 μg/m ), PM2.5 (19.11 – 28.83 μg/m), PM4.0 (24.73 – 44.63 μg/m), PM7.0 (41.07 – 67.04 μg/m ), and PM10 ranging from 65.48 – 90.82 μg/m. In addition, value of the control station was lowest amongst all recorded values of PM (p<0.05). Based on Air Quality Index evaluation, the football fields were predominantly rated as unhealthy, with other cases rates as; hazardous and unsafe for sensitive group. This investigation therefore concludes that the emission of PM from the football field are reflection of vehicular emissions and agitated dust particles. Hence mitigable measure must be applied without much ado, in order to ameliorate the daily chronic exposure to PM. JOURNAL OF EXPERIMENTAL AND CLINICAL TOXICOLOGY ISSN NO: 2641-7669 Research DOI: 10.14302/issn.2641-7669.ject-19-2595 Corresponding author: Tariwari C.N Angaye, Department of Biological Science, Faculty of Science, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria, Email: maktarry@yahoo.com


Introduction
Air pollution is the release of substances that are capable of infringing on ambient quality of the air [1,2].
The adverse effects of the pollutant might be acute or chronic, depending on the on the specie, concentration, physical, biological or chemical properties of the pollutant [3]. Pollution is also seen as a process that involves the infringement of the environment by substances capable of inducing adverse effects to the environment including other forms of biota [4,5,6]. Air pollutants includes organic or inorganic agents such as particulate matter, microbes, heavy metals, metabolites etc [2]. Statistically, on annual basis there are over two million global cases of mortality linked to air pollution, with adverse effects on the respiratory system [7].
Furthermore, most cases of mortalities were due to emission of fine PM whose size is less than 2.5 µm in diameter [7,8].
Particulate matter is a compounding aggregation of solid or liquid particulates that is suspended or persistent in the air over a period of time. Particulate matter vary in sizes, notwithstanding, they are broadly characterized as fine (≤2.5 µm), and coarse PM whose diameter is greater than 2.5 µm. Finer PM poses more health problems due to their ability to penetrate the lung as opposed to coarse and larger PM [8]. For instance, PM1.0 which is a fine PM and rated as the most lethal, with cases of infant mortality and heart problems [9].
As established in literature by Araújo et al., [1], in the regulatory determination of the extent of pollution in any country, it is habitual to establish references backgrounds. These air quality background will be become standards that describe the threshold concentration of air pollutant, whose exceedances can affect biodiversities [1,10]. Currently, there are no comprehensive air quality backgrounds for most developing countries as most researchers often depends on guideline from the World Health Organisation [11].
The study area (Yenagoa Metropolis), is the State Capital Territory of Bayelsa State. It is a wet land located on the southernmost part of Nigeria. It has a deltaic landmass, and characterized by shallow aquifer with several networks of creek and creeklets. It have two prevailing seasons, which are dry and wet season.
During the dry season it is usually windy and dusty with no precipitation, while in wet season there is high level of precipitation [12]. Yenagoa metropolis is the capital city of Bayeslsa state, and with dusty football field having poor vegetation cover, in addition to their proximity to traffic zone. Engagement of this field for sporting activities might induce exposure to suspended particulate matter. As such this investigation has become necessary.

Sampling
The sampling of particulate matter was carried out in 4 randomly selected football field, and a control station (a garden). The four sampling stations were randomly selected with distance of about 1km apart, while the control station had a distance of over 2km. Portable Metone AEROCET 531 Particulate matter meter was used during the sampling. During sampling, the meter was power on with the probe facing the windward direction. The meter runs for approximately 1 minute, after which the result was ready for reading on the screen. Depending on the sizes of the particulate matter, the meter spetiates particulates based on their diameter per cubic meter (µg/m 3 ). As such particulates are characterized as PM1.0, PM2.5, PM4.0, PM7.0, PM10 and Total Suspended Particulate (TSP).

Air Quality Index (AQI)
The Air Quality Index (AQI) is a model scheme developed to quantify the health risk for air quality in the atmosphere, based on individual air quality and a certain reference of background value. This may include; geometric mean, control or the regulatory limit value of the geographical area [13,14]. The health risk was calculated using the AQI scheme of Lingan et al., [13], with slight modification. The health risk values were calculated using the AQI equation below. Furthermore, magnitude of the health risk were interpreted based on value ranges, with different colour codes as presented in

Result and Discussion
Result on the spatial levels of particulate matter associated with the football field is presented in Figure   1. Based on spatial distribution of the football field, higher levels of PM1.0 particulate matter ranging from 13.33 -20.39 µg/m 3 was reported, compared to the control station that had the lower value (9.97 µg/m 3 ).
However, the highest level of PM1.0 particulate matter was reported in station L4 (Figure 1). On the other hand the lowest value was reported in station L1. Moreover, based on the model for health risk of PM1.0 particulate matter associated with the football field indicated that it was unsafe for sensitive group in station L1. An unhealthy condition was indicated in stations; L2 and L3, while station L4 indicated a very unhealthy condition ( Table 2).
The level of PM2.5 particulate matter associated with the football field ranged from 19.11 -29.83 µg/m 3 . The highest value was reported in station L4, while the lowest value was reported in station L1 (Figure 1). In addition, the control station (13.27 µg/m 3 ) indicated the lowest level of PM2.5 particulate matter (Figure 1). Based on the model for health risk assessment, the levels of PM2.5 particulate matter station L1 was unsafe for sensitive group, stations L2 and L3 were unhealthy, while station L4 was very unhealthy ( Table 2).
Based on spatial distribution, the levels of PM4.0 particulate matter in the football field ranges from 24.73 -44.63 µg/m 3 , with a much more lower value in the control station (19.45 µg/m 3 ) as presented in figure   1. In addition the highest level of PM4.0 particulate matter was reported in station L4, while the lowest value was reported in station L1 (Figure 1). Based on health risk assessment, PM4.0 particulate matter it was unsafe for sensitive group in station L1. Meanwhile it was unhealthy in station L3 (Table 2). Stations L2 and L4 indicated a very unhealthy condition ( Table 2).
As presented in Figure 1, the spatial levels of PM7.0 particulate matter ranges from 41.07 -67.04 µg/ m 3 , with a lower value in the control station (33.41 µg/m 3 ). Meanwhile, the highest and lowest values of PM7.0 particulate matter was reported in stations L4 and L1 respectively. Based on the modelling for health risk assessment of the football field, station L4 was very unhealthy, station L1 was unsafe for sensitive group, while stations L2 and L3 was unhealthy ( Table 1). The spatial level if PM10 particulate matter associated with the football field ranges from 65.48 -90.82 µg/m 3 ( Figure 1). Meanwhile, the highest level of PM10 particulate matter was indicated in station L2, while the lowest value was indicated in station L1 ( Figure 1).
Notwithstanding, based on model for health risk assessment of the football field, stations L1and L3 were unhealthy for sensitive group, while L2 and L4 were rated to be unhealthy.
Result of this study is comparable to previous study of Angaye et al. [2], for temporal spatiation of  132.0 and 1033 to 40000 μg/m 3 were reported [16]. As reported by several authors, health cases linked to exposure of particulate matter includes but not limited to; untimely death of persons who present cases of heart or lung infection, intensified asthma, heart attacks, asymmetrical heartbeat, deteriorated lung function, and amplified respiratory symptoms which includes; coughing, irritation of the airways, or difficulty breathing [20,21,22,23].

Conclusion
Evaluation and Health Risk Assessment of Particulate Matter around football field of Yenagoa Metropolis Nigeria was investigated. Model for Air Quality Index (AQI) was used to determine the health risk. Unfortunately, most of the all the football field had significant levels of particulate matter for PM1.0, PM2.5, PM4.0, PM7.0 and PM10. Based on AQI modelling, none of the playground relatively. Health risk indications were; unsafe for sensitive group, unhealthy and very unhealthy. The levels of particulate matter emission is a reflection of anthropogenic activities from agitated dust particles from poor vegetation cover of the field, we also recommend the monitoring of air quality in public places in order to avert chronic intake of particulate matter.