Occupational health and safety management case study: Establishment of PM10 Contour map

Atmospheric dust is a significant air pollution problem. Particulate matter is small solid particles floating in the air. It is caused by objects that have been smashed, hit, crushed, and crushed until they break down into small parts. When blown by the wind, it will spread in the air. And fell to the ground the fall time is slow or fast depending on the dust particles' weight. Dust is divided into large dust, including small dust called PM10 (dust with a diameter from 10 microns down). The stone mill problem has been a long-time problem. Many related government agencies try to fix the problem of dust pollution and health safety. PM10 disperse from the source to the community nearby the stone mill was measured by the low-cost dust monitoring device. The result found that the 24-hour mean PM10 particulate matter was 0.090 mg/m3, which was also lower than the statutory permissible 24-hour Mean PM10 at no more than 0.12 mg/m3. The PM10 dust contour map can be used for health risk management planning, primarily to mitigate the pollution to the community environment and their health under some usage limitations changes.


Introduction
The stone crushing factory that processes stone to different sizes will be transformed into smaller sizes according to the user's order, whether used in construction or other forms of work, the stone according to its characteristics and delivering it to the customer who made the order. Each step of the process caused dust dispersion. These dust sources are obtained from mountain blast rocks and processed by sieving them on a sieve for different sizes, the stone used as building materials. Buildings, roads, roads, and other utilities, but at the same time, there are environmental problems and impacts on the community regarding noise-pollution and safety matter.
The environment is significantly affected by air quality. Many studies try to expose the relationship between air pollution and the quality of life and health. Air pollution fades respiratory functions and cardiovascular problems and increases asthma rates [1]. The air pollutants indicate powerful flexibility; their intensities vary according to region. Each pollutant's inconsistency is also high because of various factors, such as pollutant type and atmospheric circumstances [2][3][4][5].
Sensor technology generates data at an unprecedented rate and scale to the rapid adoption of low-cost dust monitor for air quality monitoring. The measurements of all target devices, which were corrected according to the reference device, provided accurate values at PM2.5 concentrations of≥40 µg/m 3 . The statistical analysis results suggest that the evaluated devices are more reliable than the conventional numerical-analysis-based monitoring system [6].
A Low-Cost Particulate Matter (PM10) Smart Sensor was modeled and applied for environmental risk assessment from the stone crushing industry in Kanchanaburi province, Thailand.
Dust distribution and environmental problems in this area are considered one of the issues that the researchers wanted to communicate with interested parties and those affected by dust pollution. Find out from the research results to guide the use of the PM10 Contour map. This information will be used as a guideline for planning the operations, Preventing and correcting the problem from PM10 effect from dust source to the nearby community in the future.

Method of measurement
 Preparing of the Measurement device and person who had to use this device, set up the measurement plan such as  Time and period to measure and locations for measuring.  Measuring follows the planning  Collecting, Analyzing, and summarize from data  Evaluate the air quality against Thai regulation. Table 1.

Establishment of PM10 contour line
The data obtained from the measurement point was used as data input for a ready-made program for plotting the PM10 Contour map shown in Fig.2.

Reliability Test
Measurement at the coordinate shown in the map 3 points of test points and results shown in Table 2. On the day of checking the PM10 Contour Line map usage, the temperature was between 33-34 degrees Celsius, the average relative humidity was between 43-48% and the wind speed was between 1.5-1.9 meters per second, blowing from south to north.

Conclusion
PM10 contour map illustrated that PM10 dust concentration characteristics from dust sources would have the highest value at the commencement of dust. There will be a concentration of dust. However, the PM10 value may vary from temperature, humidity, wind speed, and wind direction factors. It depends on the magnitude of the factors affecting to PM10 value. But for this research, these factors are less effective than the distance factor from the dust source. Then the PM10 Contour Map can present the dust concentration line map is available to use subject to the following conditions: temperature of the area. It should be between 25-32 degrees Celsius, the relative humidity of the site. It should be between 53-83%, and the wind speed should be between 0.93-2.33 m/s. The observed distance should not exceed 2.5 km.
The direction of wind blowing from south to north will give results that work correctly and adequately. However, from the data for the measurement of PM10 from dust sources, the 24-hour mean value was 90.19 μg/m 3 , still within the allowable regulation limit. That does not exceed the statutory value is 120 μg/m 3 [8]. In contrast, the PM10 value measured at the education community, which is far from about 2.5 kilometers of origin, PM10 was found to have a 24hour mean of 71.37 μg/m 3 that still lower than the legal limit.