Environmental Management (MN/GM 365) PDF

UNIVERSITY OF MINES AND TECHNOLOGY FACULTY OF GEOSCIENCES AND ENVIRONMENTAL STUDIES (FGES) ENVIRONMENTAL MANAGEMENT MN/GM 365 L. B. OSEI (PhD) 2025...

UNIVERSITY OF MINES AND TECHNOLOGY FACULTY OF GEOSCIENCES AND ENVIRONMENTAL STUDIES (FGES) ENVIRONMENTAL MANAGEMENT MN/GM 365 L. B. OSEI (PhD) 2025 Saturday, 08 February 2025 1 Saturday, 08 February 2025 2  Course Outline The Mining Environment Air parameters Gases Dust/Particulates Detection of Gases and Particulates Air Pollution Heat in the Work Environment/Thermal Stress Water Quality and Pollution Instruments Used in Water Quality Analysis Environmental Impact Assessment Saturday, 08 February 2025 3  Course Aims This course is designed to; Provide students to the concepts of the mining environment, environmental pollution and management. Help students gain a better understanding of the pollutants released into the environment by mining activities, how these pollutants affect the environment, and how these pollutants are measured and managed. Saturday, 08 February 2025 4  Course Assessment Assessment will be as follows; Quizzes/individual and group assignment - 30% Class exercise /attendance -10% Final examination -60% Saturday, 08 February 2025 6  CHAPTER ONE THE MINING ENVIRONMENT Saturday, 08 February 2025 7  The Environment The environment can be defined as the physical and biological habitat that surrounds us, which can be felt by our physical faculties. (i.e., seen, heard, touched or felt through the skin, smelled and tasted). Most jurisdictions now define the term broadly to include not only physical/chemical and biological but also social, cultural, and economic aspects, and by implication refer to the environment of people. The general characteristics of the physical/chemical (air, water, and land), biological (fauna and flora), and human environment (social and economic systems). Saturday, 08 February 2025 8  The Environment...Cont’d In natural sciences and physical geography (the ‘hard’ sciences) there are four environmental spheres, namely atmosphere (‘air’), hydrosphere (‘water’), lithosphere (‘land’), and biosphere (‘fauna and flora’), in an intricately interlocked natural system. On this natural system we have erected our own human environment, modifying, altering, or destroying natural conditions that existed before human impact (sometimes coined ‘built environment’ as compared to natural environment). Saturday, 08 February 2025 9  The Environment...Cont’d Apart from human influences on the natural environment, our environment is also defined by demographics, by manmade systems and structures and by cultural and heritage resources. In social sciences and human geography (the ‘soft’ sciences). The human factor is grouped into social and economic systems, or the social and economic spheres. Saturday, 08 February 2025 10  The Environment...Cont’d Saturday, 08 February 2025 Source: Spitz and Trudinger (2019) 11  The Environment...Cont’d The environmental assessment of a new mining project will cover all six environmental spheres, the overlapping areas of the three circles of sustainability. Each mining project will influence all these spheres, and all of them will influence the mine. Saturday, 08 February 2025 12  Environmental Management Environmental Management or Environmental Resources Management is the management of the impact of human activities on the environment. More specifically, we say it is a systematic approach to finding practical ways of saving water, energy, and other natural resources, and reducing negative environmental impacts. Some of the dominant study themes include environmental degradation and natural resource use, natural hazards and impact assessment, and the effects of urbanization and land use. Saturday, 08 February 2025 13  CHAPTER TWO THE ATMOSPHERE Saturday, 08 February 2025 14  The Atmosphere – Air, Weather and Climate Mining projects are influenced by the climatic conditions experienced at the mine site. Temperature, precipitation (or lack of it), visibility, wind, and their variations are all important factors in the design and operation of mining and processing facilities. Mining and mineral processing, however, can also influence climatic conditions, at local and global scales, but more importantly can impact local air quality affecting human health and comfort. Hence, the importance of understanding local climate and air quality. Saturday, 08 February 2025 15  The Atmosphere...Cont’d The atmosphere is the gaseous envelop surrounding the earth and is the most dynamic and changeable of the "spheres" of the earth (i.e., the hydrosphere, biosphere and lithosphere). It is a complex system in which physical and chemical reactions are constantly taking place. Many atmospheric processes take place in a state of dynamic balance — for example; there is an average balance between the heat input to, and output from, the atmosphere. Saturday, 08 February 2025 16  The Atmosphere...Cont’d Other examples include; 1. Balance between solar energy entering and radiant energy leaving the atmosphere. 2. Levels of oxygen in the atmosphere are regulated by photosynthesis and and respiration. 3. Water levels are regulated by the hydrological cycle. Saturday, 08 February 2025 17  The Atmosphere...Cont’d Constituent (Symbol) Concentration by volume % Nitrogen (N2) 78.1 Oxygen (O2) 20.9 Water vapour (H2O) 0 –5, variable Argon (Ar) 0.9 Carbon dioxide (CO2) 0.03 Trace constituents* Balance *The trace constituents include Helium (He), Neon (Ne), Krypton (Kr), Xenon (Xe), Sulfur dioxide (SO2), Nitrogen dioxide (NO2), Methane (CH4), Nitrous Oxide (N2O), Ammonia (NH3), Ozone (O3), and Carbon monoxide (CO) etc. Saturday, 08 February 2025 18  The Atmosphere...Cont’d The vertical temperature profile in the atmosphere Saturday, 08 February 2025 19  The Atmosphere (Temperature) The maximum air temperature occurs near the Earth’s surface in the troposphere. Air temperature declines uniformly with altitude at a rate of approximately 6.5 degree Celsius per 1,000 metres, a phenomenon termed environmental lapse rate. Much of the Earth’s climatic variation results from uneven heating of its surface by solar radiation or by uneven lateral distribution of temperature, caused by the spherical shape of the Earth and the angle at which the Earth rotates on its axis as it orbits the sun. Saturday, 08 February 2025 20  The Atmosphere (Temperature)...Cont’d About half of the energy received from the sun in the form of solar radiation is absorbed by the land and the oceans. To maintain the Earth’s long-term mean surface temperature of 16°C, however, the Earth must lose heat as well as gain it. The energy gained by the surface must be transferred to the atmosphere, with the result that on average, our atmosphere is primarily heated from below by heat given off from the Earth. This means that the atmosphere is set into convective motion. Saturday, 08 February 2025 21  The Atmosphere (Temperature)...Cont’d Understanding the climate at a specific location on the Earth, such as a mine site, usually requires long-term meteorological measurements at the particular location. Saturday, 08 February 2025 22  The Atmosphere (Temperature)...Cont’d Temperature is an air parameter measured with a thermometer, and it is measured in either degrees Celsius (℃) or in degrees Fahrenheit (℉). Absolute temperature in Kelvin, K = t (℃) + 237 K Absolute temperature in Rankine, R = t (℉) + 459 R Saturday, 08 February 2025 23  The Atmosphere (Temperature)...Cont’d Temperature conversion; Degree Celcius to Fahrenheit 𝟓 𝑻 ℃ = ∙ (𝑻 ℉ − 𝟑𝟐) (1) 𝟗 Degree Fahrenheit to Celcius 𝟗 𝑻 ℉ = ∙ (𝑻 ℃ + 𝟑𝟐) (2) 𝟓 Saturday, 08 February 2025 24  The Atmosphere (Temperature)...Cont’d Dry Bulb Temperature – Tdb Dry bulb temperature refers to the ambient air temperature. This is the temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture. It indicates the amount of heat in the air and is directly proportional to the mean kinetic energy of the air molecules. Unlike wet bulb temperature, dry bulb temperature does not indicate the amount of moisture in the air. Saturday, 08 February 2025 25  The Atmosphere (Temperature)...Cont’d Wet Bulb Temperature – Twb The wet-bulb temperature is the temperature a parcel of air would have if it were cooled to saturation (100% relative humidity) by the evaporation of water into it, with the latent heat being supplied by the parcel. Wet-bulb temperature is the temperature of adiabatic saturation. The wet-bulb temperature is the temperature a parcel of air would have if it were cooled to saturation (100% relative humidity) by the evaporation of water into it, with the latent heat being supplied by the parcel. Saturday, 08 February 2025 26  The Atmosphere (Temperature)...Cont’d Dew Point Temperature – Tdp The dew point is the temperature where water vapour stars to condense out of the air (the temperature at which air becomes completely saturated). Above the is temperature the moisture stays in the air. If; a. The dew point temperature is close to the dry air temperature – the relative humidity is high. b. The dew point temperature is well below the dry air temperature – the relative humidity is low. If moisture condenses on a cold bottle taken from the refrigerator, the dew point temperature of the air is above the temperature in the refrigerator. Saturday, 08 February 2025 27  The Atmosphere (Temperature)...Cont’d Dew Point Temperature – Tdp The dew point temperature is always lowere than the dry bulb temperature and will be identical with 100% relative humidity. As air temperature changes the dew point remains constant unless water is added or removed from the air. Saturday, 08 February 2025 28  The Atmosphere (Temperature)...Cont’d Wet Bulb Global Temperature (WBGT) The Wet Bulb Global Temperature (WBGT) is a measure of heat stress in direct sunlight, which takes into account; temperature, humidity, wind speed, sun angle and cloud cover (WBGT). It is used by industrial hygienists, athletes, and the military to determine appropriate exposure levels to high temperatures. Saturday, 08 February 2025 29  The Atmosphere (Temperature)...Cont’d Wet Bulb Global Temperature (WBGT) 𝑊𝐵𝐺𝑇 = 0.7 𝑇𝑤 + 0.3 𝑇𝑔 + 0.1 𝑇𝑑 (2) Where; Tw = wet bulb temperature Tg = globe temperature, measured using a black globe thermometer to assess radiant temperature. Td = dry bulb temperature (actual air temperature) Temperatures may be in either ℃ or ℉. Saturday, 08 February 2025 30  The Atmosphere (Pressure) Pressure refers to the force exerted perpendicular to the surface of an object per unit area over which that force is distributed. It is measured in N/m2 or Pa. Pressure may be Absolute or Gauge (Pressure Difference). Atmospheric pressure (P) or Barometric pressure is absolute pressure and it is measured with a barometer. Saturday, 08 February 2025 31  The Atmosphere (Humidity) It is the amount of water vapour in the air. The higher the air temperature the larger the quantity of water vapour it can contain. When air at a particular temperature contains its maximum amount of water vapour it is said to be saturated. Absolute Humidity The quantity of water vapour expressed in g per m3 of air. 𝑀𝑎𝑠𝑠 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟 𝑣𝑎𝑝𝑜𝑢𝑟 (𝑔) Absolute Humidity = (3) 𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑎𝑖𝑟 (𝑚3 ) Saturday, 08 February 2025 32  The Atmosphere (Humidity)...Cont’d Relative Humidity (𝛗) The ratio of the mass of water to the total mass of the moist air parcel or the ratio of vapour pressures of air (Pv) at a given condition and at saturation (Psat). When the air is saturated with moisture and cannot hold any more water vapor, the relative humidity is 100%. 𝐴𝑐𝑡𝑢𝑎𝑙 𝑤𝑎𝑡𝑒𝑟 𝑣𝑎𝑝𝑜𝑢𝑟 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒 (𝑃𝑣 ) 𝑅𝐻 = × 100 𝑆𝑎𝑡𝑢𝑟𝑎𝑡𝑒𝑑 𝑤𝑎𝑡𝑒𝑟 𝑣𝑎𝑝𝑜𝑢𝑟 𝑝𝑟𝑒𝑠𝑠𝑢𝑟𝑒 𝑎𝑡 𝑡ℎ𝑎𝑡 𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 (𝑃𝑠𝑎𝑡 ) (4) Saturday, 08 February 2025 33  The Atmosphere (Humidity)...Cont’d Specidfic Humidity (x) It is the weight (in kg or g) of water vapour per unit weight of dry air. Unlike relative humidity, specific humidity is not dependent on temperature changes. If we know the relative humidity of the moist air and the water vapor density and the density of the air, the specific humidity can be expressed as: φ∙ρws x = 0.622 × (5) ρ −ρws 100% where x = specific humidity (humidity ratio) of air vapor mixture (kgH2O/kgdry air) φ = relative humidity (%) ρws = density of water vapor (kg/m3) ρ = density of the moist or humid air (kg/m3) Saturday, 08 February 2025 34  The Atmosphere (Humidity)...Cont’d High humidity can often have a negative effect on the capacity of chemical plants and refineries that use furnaces as part of a certain processes (e.g., steam reforming, wet sulphuric acid processes). For example, because humidity reduces ambient oxygen concentrations (dry air is typically 20.9% oxygen, but at 100% relative humidity the air is 20.4% oxygen), flue gas fans must intake air at a higher rate than would otherwise be required to maintain the same firing rate. Saturday, 08 February 2025 35  The Atmosphere (Precipitation) Precipitation is a critical variable for establishing water balances and their variability. Precipitation includes fallen (liquid or solid, i.e. rain, snow, and hail) as well as deposed (dew or frost) forms. The observed variable is precipitation depth, defined as the depth of liquid water accumulated during a defined time interval on a horizontal surface. Hence, precipitation is measured in mm per time interval. Saturday, 08 February 2025 36  The Atmosphere (Precipitation)...Cont’d Precipitation drives the land surface hydrology in the same way that incoming solar radiation drives the surface thermal regimes. It is therefore the key variable in the terrestrial hydrological cycle (surface water budget), and is essential for all vegetation growth. Reliable, high resolution records of precipitation are critical inputs for the design of mining projects, for understanding and monitoring regional effects of project development on hydrology, and for estimating water availability (or respectively water scarcity) for project consumption. Saturday, 08 February 2025 37  The Atmosphere (Precipitation) )...Cont’d For most applications (water cycle and budget), area averaged information on precipitation is sufficient. Saturday, 08 February 2025 38  The Mine Atmosphere Atmospheric parameters can influence air quality and noise. As atmospheric air pumped or blown into underground mining excavations passes through the mine excavations, the air undergoes changes in composition, temperature, and humidity. In comparison with surface atmospheric air, mine air often contains less O2 but more N2 and CO2 because of oxidising processes and the release of CO2 from rocks. In addition, mixtures of poisonous and explosive gases, vapours, and dust may be present. In normal mine atmospheres, the content of O2 is not less than 20 percent and the content of weakly toxic CO2 is not more than 0.5–1 percent. Saturday, 08 February 2025 39  The Mine Atmosphere Mine air may be contaminated by the presence of other gases such as CO, SO2, H2S, CH4, NOx and excess CO2. Schematic diagram of the airflow within a mine Saturday, 08 February 2025 40  CHAPTER THREE AIR POLLUTION Saturday, 08 February 2025 41  Air Pollution Air pollution can be defined as the introduction of a substance (i.e., pollutant) in the atmosphere that is harmful to human and the environment. It can be either natural or man-made, and occur both indoor and outside. Although natural emissions of air pollution may affect the environment from time to time, man-made air pollution leads to poor air quality on a more regular basis. Saturday, 08 February 2025 42  Air Pollution Air pollution is a major problem since very long. In the Middle Ages, the burning of coal released large amounts of smoke and sulphur dioxide to the atmosphere. In the late 18th century, the Industrial Revolution led to escalation in pollutant emissions by the industry. After the disastrous London Smog (Great Smog) of 1952, estimated to have left about 12,000 people dead within four days, pollution from industries and homes was sought to be reduced to prevent recurrence of these events. Saturday, 08 February 2025 43  Emission And Sources Of Air Pollutants Emission is the amount of pollutant a source releases into the air. The rate of emission is expressed as the mass per time (e.g., g/s, kg/day or tons per year). Saturday, 08 February 2025 44  Emission And Sources Of Air Pollutants Air pollutants have their sources from four (4) main types: 1. mobile sources – such as cars, buses, planes, trucks, and trains 2. stationary sources – such as power plants, oil refineries, industrial facilities, and factories 3. area sources – such as agricultural areas, cities, and wood burning fireplaces 4. natural sources – such as wind-blown dust, wildfires, and volcanoes Saturday, 08 February 2025 45  Emission And Sources Of Air Pollutants Saturday, 08 February 2025 46  Mine Gases Saturday, 08 February 2025 47  Mine Gases (Air Pollutants) Mine air may be contaminated by the presence of other gases such as CO, SO2, H2S, CH4, NOx and excess CO2. Due to being in a confined space these gases are not always able to disperse and can therefore build up in the mine, and due to their combustible, explosive, or toxic qualities this is a serious issue. Rather than one particular gas they are a toxic or explosive mixture of different gases that have a varying effect on human health and mine safety Saturday, 08 February 2025 48  Mine Gases (Air Pollutants)...Cont’d Mine air may be contaminated by the presence of other gases such as CO, SO2, H2S, CH4, NOx and excess CO2. Mixtures of gases found in mine environments are called damps. Black Damp: Carbon dioxide and nitrogen in an oxygen deficient atmosphere which will cause suffocation. Black damp is the mining term for the suffocating mixture of carbon dioxide and other unbreathable gases that can build-up in mines causing poisoning, asphyxiation, and ultimately death if left untreated Saturday, 08 February 2025 49  Mine Gases (Air Pollutants)...Cont’d Black Damp: The fact that blackdamp will always be present where coal is present and that it is hard to identify and distinguish between fatigue, increases the risk that warning signs will be missed allowing blackdamp to cause serious harm within seconds. Therefore prevention of black damp and identification of the dangerous gases is essential for mine safety. White Damp: Carbon monoxide (CO). Very poisonous. White damp is a mixture of poisonous gases found in coal mines and is predominantly made up of carbon monoxide (CO). Saturday, 08 February 2025 50  Mine Gases (Air Pollutants)...Cont’d White Damp: Infamously, the domestic canary was used as an early warning against any noxious gases in the past. This is because carbon monoxide affects small animals more quickly than humans, and when exposed to carbon monoxide the bird would fall from their perch alerting the miners to move to safety. There is now modern equipment that can easily detect carbon monoxide without any cost to life. Saturday, 08 February 2025 51  Mine Gases (Air Pollutants)...Cont’d Stink Damp: Hydrogen Sulfide (H2S). It is colorless, has a sweetish taste, and a very distinctive odor of rotten eggs. As little as 0.01% in air being capable of detection by this means. The gas is even more poisonous than CO. Saturday, 08 February 2025 52  Mine Gases (Air Pollutants)...Cont’d Fire Damp: Firedamp is a mining term for a set of explosive gases found in mines. It’s mostly made up of methane (CH4) and methane is often an interchangeable term when miners talk about firedamp. Any dangerous gases must be detected and monitored. This was often done through the use of a testing flame. Originally a candle with a naked flame would be an indicator of an unsafe atmosphere depending on the change to the flame tip. As you can imagine, a flame is a pretty clear means of ignition, so when it got too close to the gas explosions would take place. Saturday, 08 February 2025 53  Mine Gases (Air Pollutants)...Cont’d After Damp: Gaseous products and smoke produced by a fire or explosion which includes the following gases: CO, CO2, water vapor, nitrogen, oxygen, hydrocarbons and hydrogen. Saturday, 08 February 2025 54  Mine Gases (Air Pollutants)...Cont’d The presence of these gases may be due to any of the following: 1. After effects of blasting or other explosions. 2. After effects of mine fires. 3. Liberation from ore or country rock, as with methane. 4. Decay of timbers in poorly ventilated areas. 5. Absorption of oxygen by water or oxidation of timber or ore. 6. Use of diesel and gasoline motors in enclosed areas. 7. Gas carried with thermal water or carbon dioxide. 8. Gas carried chemically by various chemicals and reagents. Saturday, 08 February 2025 55  Mine Gases (Air Pollutants)...Cont’d Except in cases of fire, positive ventilating currents of sufficient quantity will prevent any dangerous accumulation of these gases. Gases may affect people either by their combustible, explosive, or toxic qualities, or, if inert, by the displacement of oxygen. Saturday, 08 February 2025 56  Mine Gases (Air Pollutants)...Cont’d Saturday, 08 February 2025 57  Mine Gases (Air Pollutants)...Cont’d These damps are produced or released during mining operations including drilling and blasting, by mining machinery such as diesel and gasoline motors, and by other means such as the decay of timbers, the aftereffects of mine fires, and chemical processes like oxidation. The most efficient way of preventing these gases in mines is the incorporation of high quality mining ventilation systems as well as the use of early detection devices. Saturday, 08 February 2025 58  Mine Gases (Air Pollutants)...Cont’d Group Assignment Group 1 – 1. Carbon monoxide 2. Nitrogen oxides (NOx) 3. Hydrogen Sulphide Group 2 - 1. Methane 2. Sulphur oxides (SOx) 3. Carbon dioxide Saturday, 08 February 2025 59  Mine Gases (Carbon Dioxide (CO2))Cont’d Carbon dioxide is an inert gas which is a product of the decomposition and/or combustion of organic compounds in the presence of oxygen. Carbon dioxide is also produced by respiration of people and animals. It is a colorless, odorless gas which, when breathed in large quantities, may cause a distinctly acid taste. It will not burn or support combustion. Saturday, 08 February 2025 60  Mine Gases (Carbon Dioxide (CO2))Cont’d The specific gravity of carbon dioxide is 1.5189. Carbon dioxide, being heavier than air, is often found in low places and abandoned mine workings and is a normal constituent of mine air. Carbon dioxide in mine air is increased by breathing, burning of flame lamps, fires, explosions, blasting or by escaping with thermal water. Carbon dioxide is also liberated from some coal beds. Saturday, 08 February 2025 61  Mine Gases (Carbon Dioxide (CO2))Cont’d Physiological Effects of Carbon Dioxide Carbon dioxide in air has these effects when the oxygen content remains approximately normal and the individual is at rest. Moving around or working increases symptoms and danger is greater than when the individual is resting. Saturday, 08 February 2025 62  Mine Gases (Methane (CH4))...Cont’d Methane is encountered in practically all coal mines. Methane is formed by decomposition of organic matter in the presence of water and the absence of air or oxygen. In a coal mine, methane may be emitted from the cleats or cracks of the coal, from "blowers" or "feeders", or from overlying or underlying strata. It is often released in large amounts from the coal when irregularities, such as clay veins, "horsebacks," or faults occur. Once liberated from the strata, methane tends to accumulate near the mine roof or in high places where it mixes progressively with air currents and eventually may be found uniformly distributed across a cross section of airflow. Saturday, 08 February 2025 63  Mine Gases (Methane (CH4))...Cont’d Once mixed with fresh air, it will no longer separate into layers or form pockets of still gas. The specific gravity of methane is 0.555. Methane is considerably lighter than air and when found at mines it is usually in high places near the roof. The ignition temperature of methane is 537 °C. Methane is a colorless, odorless and tasteless gas. An odor caused by the presence of other gases such as hydrogen sulfide often accompanies it. Methane will burn with a pale blue nonluminous flame. Saturday, 08 February 2025 64  Mine Gases (Methane (CH4))...Cont’d Still air that contains 5 to 15 percent methane and 12 percent or more of oxygen will explode--this is its chief danger. Occurrences of methane, if suspected or known, should be diluted with the help of adequate ventilation. Methane is most often detected by a methane detector. Methane has no direct effect upon workers but it may displace the oxygen content of air to such an extent as to cause oxygen deficiency. Saturday, 08 February 2025 65  Mine Gases (Methane (CH4))...Cont’d It is required that electrical circuits be isolated in any work area when the methane content in the general body of air in that area reaches 1.0 percent. It is also required that all miners be withdrawn from any work area when the methane content of the general body of air in that area reaches 1.5 percent. No blasting or shot-firing is to be done when methane content exceeds 1.0 percent. Explosiveness of coal dust increases in the presence of methane and coal dust in turn decreases the lower explosive limit of methane. Saturday, 08 February 2025 66  Mine Gases (Carbon Monoxide (CO))...Cont’d CO gas constitutes one of the greatest hazards to life in mining. CO is a product of combustion in normal blasting operations and in the use of diesel motors (incomplete combustion). It is dangerous unless adequate ventilation is provided. CO will burn and air that contains 12.5 to 74 percent of carbon monoxide will explode if ignited. It is only slightly soluble in water and is not removed from the air to any extent by water sprays. Saturday, 08 February 2025 67  Mine Gases (Carbon Monoxide (CO))...Cont’d It is slightly lighter than air having a specific gravity of 0.967. The ignition temperature of CO is 609 °C. CO in excess of 0.01 percent, if breathed indefinitely, may eventually produce symptom of poisoning; 0.02 percent will produce slight symptoms after several hours’ exposure. When 400 ppm(0.04 percent) is present and the exposure is from 2-to-3 hours, headache and discomfort usually occur. Saturday, 08 February 2025 68  Mine Gases (Carbon Monoxide (CO))...Cont’d With moderate exercise, when 0.12 percent is present, slight palpitation of the heart will occur in 30 minutes, tendency to stagger in 1.5 hours, and confusion of mind, headache and nausea in 2 hours. In concentrations of 1.20 to 0.25 percent, unconsciousness usually occurs in about 30 minutes. The effect of high concentrations may be so sudden that one has little or no warning before collapsing. The carbon monoxide content of the air in which workers are employed for a period of 8 hours should not exceed 0.005 percent or 50 ppm. Saturday, 08 February 2025 69  Mine Gases (How CO Acts)...Cont’d Oxygen absorbed from air in the lungs is normally taken up by the blood in the form of a loose chemical combination with the haemoglobin of the red blood cells. Oxygen is carried in this form to the tissues where it is used. Hemoglobin forms a stable compound with CO (higher affinity) than with oxygen. Therefore, even when a small percentage of carbon monoxide is present in inhaled air, hemoglobin will absorb the carbon monoxide in preference to the oxygen. Saturday, 08 February 2025 70  Mine Gases (How CO Acts)...Cont’d This interference with the oxygen supply to the tissues produces the symptoms of CO poisoning. The symptoms of carbon monoxide poisoning more or less parallel the extent of blood saturation. Symptoms decrease in number as the rate of saturation increases. If exposed to high concentrations the victim may experience but few symptoms. The rate at which a person is overcome and the sequence in which symptoms appear depends upon the concentration of gas, extent to which the person is exercising, the victim's health, individual susceptibility, temperature, humidity and air movement. Saturday, 08 February 2025 71  Mine Gases (How CO Acts)...Cont’d Experiment Conducted by United States Bureau of Mines (at rest) Saturday, 08 February 2025 72 Mine Gases (Treatment for CO Poisoning)Cont’d CO poisoning may occur suddenly or gradually depending upon concentration and period of exposure. The most important concerns in treatment are to rest and avoid further exposure to the gas. The most important thing in treatment of acute CO poisoning is to remove gas from the victim's blood as rapidly as possible. The natural elimination of carbon monoxide will start as soon as the patient begins to breathe air free of carbon monoxide (This is slow and may have serious effects). Saturday, 08 February 2025 73 Mine Gases (Treatment for CO Poisoning)Cont’d The steps for effective treatment of carbon monoxide poisoning are as follows: 1. Move the victim to fresh air as soon as possible. 2. If respiration has stopped, is weak and intermittent, or present only in occasional gasps, give artificial respiration until normal breathing is resumed, or until it is definitely established that the patient is dead. 3. Administer pure oxygen as soon as possible and continue as long as necessary (at least 20 minutes in mild cases and as long as 1 or 2 hour in severe cases). Immediate inhalation of oxygen for 20 to 30 minutes will significantly lessen the severe effects of carbon monoxide poisoning and lessen the chance of serious after-effects. 4. Aid circulation by rubbing the patient’s limbs (toward the heart). Keep the victim warm with blankets, hot water bottles, etc. 5. Keep the victim lying down to avoid strain on the heart and allow plenty of time to rest and recuperate. Saturday, 08 February 2025 74  Mine Gases (CO)...Cont’d Physiological Effects of Carbon Monoxide Saturday, 08 February 2025 75  Mine Gases (Oxides of Nitrogen (NOx))Cont’d Oxides of nitrogen are formed in mines by burning of explosives and, to a lesser extent, by their detonation. Oxides of nitrogen can usually be detected by the burnt powder odor familiar to blasters and by the reddish color of nitrogen dioxide (NO2) fumes, which are formed when nitric oxide (NO) produced by an explosion comes in contact with air. Gases collected from the burning of 40 percent gelatin dynamite contain 11.9 percent oxides of nitrogen. Diesel engines also produce oxides of nitrogen. Saturday, 08 February 2025 76  Mine Gases (Oxides of Nitrogen)...Cont’d Physiological Effects of Oxides of Nitrogen Saturday, 08 February 2025 77  Mine Gases (Oxides of Nitrogen (NOx))Cont’d A person exposed to dangerous concentrations of nitrogen dioxide may feel no discomfort for several hours after the end of exposure. As much as eight hours after exposure the victim's lungs may become filled with fluid resulting in asphyxia. When air samples are analyzed for oxides of nitrogen, the results usually are reported in terms of nitrogen dioxide (NO2), since this designation gives proper evaluation of the toxic properties of the atmosphere. The threshold limit value (TLV) of oxides of nitrogen is 5 ppm. Saturday, 08 February 2025 78  Mine Gases (Sulphur Dioxide (SO2))...Cont’d SO2 is produced by burning sulfide ores (pyrites) or by blasting in sulphide ores or explosions of sulfide ore dust. Some diesel fuels produce SO2. Sulfur dioxide is not combustible. This gas has a strong sulfur smell which is suffocating and very irritating to breathe. The gas affects the lungs in much the same manner as oxides of nitrogen and hydrogen sulfide. Irritation of the respiratory tract and lungs will cause pulmonary edema. Saturday, 08 February 2025 79  Mine Gases (Sulphur Dioxide (SO2))...Cont’d Physiological Effects of SO2 Sulfur dioxide is highly soluble in water--in fact it is one of the most soluble gases found in mines. It is a very heavy gas and has a specific gravity of 2.264. Sulfur dioxide is colorless with a distinctly acid taste. Saturday, The threshold limit value (TLV) of sulfur dioxide is 5 ppm. 08 February 2025 80  Mine Gases (Hydrogen Sulphide(H2S))Cont’d Hydrogen sulfide is one of the most poisonous known gases. Only traces of it are ordinarily found in mine operations. In low concentration its distinctive rotten egg odor is noticeable. In high concentrations the sense of smell is quickly paralysed by the action of the gas on the respiratory center. It is colourless and poisonous even in small concentrations. The gas has a specific gravity (SG) of 1.1763 and may collect at low points in mines. Saturday, 08 February 2025 81  Mine Gases (Hydrogen Sulphide(H2S))Cont’d The ignition temperature of Hydrogen sulfide is 260 °C. Hydrogen sulfide inhaled in a sufficiently high concentration produces immediate asphyxiation; in low concentrations it produces inflammation of the eyes and respiratory tract and sometimes leads to bronchitis, pneumonia, and edema of the lungs. The immediate effect of hydrogen sulfide is extreme irritation to the eyes. Immediate collapse usually results from exposure to concentrations of 0.06 to 0.1 percent, and death quickly follows. The 8-hour daily exposure should not exceed 0.001 percent or 10 ppm. Saturday, 08 February 2025 82  Mine Gases (Hydrogen Sulphide(H2S))Cont’d Hydrogen sulfide can be detected by hydrogen sulfide detectors. It can also be detected chemically by exposing a paper dipped in acetate which turns black immediately in presence of hydrogen sulphide. When explosions of dust occur in blasting operations in sulfide ore bodies, the resulting gases may contain varying amounts of hydrogen sulfide, along with sulfur dioxide, and possibly other sulfur gases. Hydrogen sulfide is highly explosive with an explosive range if 4.3 to 46 percent. Saturday, 08 February 2025 83  Mine Gases (Hydrogen Sulphide(H2S))Cont’d Physiological Effects of H2S Saturday, 08 February 2025 84  Dust/Particulate Matter Saturday, 08 February 2025 85  Dust/Particulate Matter (Air Pollutant) Mining and mineral processing have the potential to contribute to air pollution in various ways. Particulate matter (dust) is usually the most obvious air pollutant associated with mining. Particulate matter (PM) may well be the air pollutant that most commonly affects people’s health. Almost all mining activities that lead to the disintegration of rock such as drilling, blasting, grinding, crushing, scraping, loading, etc. produce or generate dust. Dust is popularly referred to as solid particles which can be readily dispersed into the atmosphere. Saturday, 08 February 2025 86  Dust/Particulate Matter (Air Pollutant) PM come in different shapes or sizes, and may be solid particles or liquid droplets. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope. Saturday, 08 February 2025 87  Dust/Particulate Matter (Air Pollutant) Particulate matter is the sum of small hard and liquid particles, which are not visible to the eye, that float in the lower layers of the atmosphere, which is formed by various human activities and natural activities. This complex mixture includes both organic and inorganic particles, such as dust, pollen, fumes, and liquid droplets Saturday, 08 February 2025 88  Dust/Particulate Matter (Air Pollutant) Parameters used for dust characterisation include; 1. The number of particles per unit volume. 2. The size distribution of the particles. 3. The mass of dust per unit volume. 4. The surface area of dust per unit volume. 5. The chemical composition of the dust. 6. The mineralogical nature of the particles. All these parameters depend on the type of dust, but the first four depend on the mode of dust formation as well. Dust/PM formation depends also on other factors relating to the season (weather) such as time of the day, soil moisture, temperature, humidity, wind direction and speed, rainfall, etc. Saturday, 08 February 2025 89  Dust/Particulate Matter (Air Pollutant) Dust/PM formation depends also on other factors relating to the season (weather) such as time of the day, soil moisture, temperature, humidity, wind direction and speed, rainfall, etc. Unlike other air pollutants, particulate matter is classified according to size, rather than chemical composition. Saturday, 08 February 2025 90  Dust/Particulate Matter (Air Pollutant) Based on size, particulate matter is often divide into three main groups: 1. PM10 : inhalable course particles, with diameters that are generally 10 μm and smaller; and 2. PM2.5 : fine inhalable particles, with diameters that are generally 2.5 μm and smaller. 3. PM0.1 : ultrafine particles, with is less than 0.1 μm or 100 nm. These particles undergo random (Brownian) motion and never settle. They, however, coagulate by collision and increase in size. Total suspended particulate matter (TSP) comprises of comprises solid and liquid airborne particles with diameters less than 100 μm. Saturday, 08 February 2025 91  Dust/Particulate Matter (Air Pollutant)...Cont’d How small is 2.5 micrometers? Saturday, 08 February 2025 92  Dust/Particulate Matter (Air Pollutant)...Cont’d Saturday, 08 February 2025 93  Dust/Particulate Matter (Air Pollutant) Particles above 10µm are not usually acknowledged in government health legislation, as our nose and throat filter them out. Instead, TSP is more a nuisance dust than a health risk. However, as TSP includes all particle sizes, hence, the risks associated with PM10 and PM2.5 (inhalable particles; health hazards) also apply. Particle sizes up to 200 μm, in suspension, tend to fall out at uniform or constant speed in calm air. This is because the friction of the air counteracts the acceleration due to gravity. This constant speed is called the Terminal Settling Velocity. Saturday, 08 February 2025 94  Course Inhalable Particles (PM10) PM10 known as coarse particles, is defined as all particles with an aerodynamic diameter of 10 μm or smaller. Some common sources of PM10 are: Mold spores Bacteria Dust Smoke Airborne viral particles PM10 includes any particles smaller than 10 μm in diameter, therefore, PM10 also contains fine particles (PM2.5) and ultrafine particles (PM0.1). Saturday, 08 February 2025 95  Course Inhalable Particles (PM10) Coarse particles, while not as dangerous as fine or ultrafine dust, can still pose a significant health threat. These particles can penetrate into our lungs and irritate your airways, nose, throat, and eyes. PM10 is usually created directly, with sources like construction work, road dust, or natural dust storms, rather than secondary, atmospheric sources. Saturday, 08 February 2025 96  Fine Particles (PM2.5) PM2.5 is a grouping of particles with an aerodynamic diameter of 2.5 μm or less, capable of penetrating deep into our lungs and even entering our bloodstream. Fine particles can come from natural or human-made sources such as: Vehicle exhaust Wildfires Power plant emissions Other combustion activities Saturday, 08 February 2025 97  Ultrafine Particles (PM0.1) PM0.1 is even smaller than fine particulates, with an aerodynamic of 0.1 μm or smaller, and originates from similar sources as PM2.5. Less is known about PM0.1 than PM2.5, but there is a growing body of research indicating that ultrafine particles poses a worse threat than PM2.5, as the smaller particle size can infiltrate our bodies to an even greater extent. Recent research show that PM0.1 displays enhanced cardiovascular toxicity and greater potential for oxidative stress. Ultrafine particles also represent the majority of airborne particulate matter indoors (up to 90%). Saturday, 08 February 2025 98  Pathological Effects of Dust/PM The nasal passage and oral openings through which we breathe open into the trachea (windpipe) in the throat, which in turn leads to the bronchial ramus. These tubes conduct air into the lungs, through the right and left branches. Each subdivides into many smaller tubes called the bronchioles. The bronchioles end in small sacs, the alveoli, in which the oxygenation of the blood takes place Saturday, 08 February 2025 99  Pathological Effects of Dust/PM The respiratory system has many built-in safeguards to protect the sensitive tissue in the lungs from the harmful effects of dust particles. 1. Hairs in the nasal passage filter out many of the larger particles (over 10 μm in size) entering during inhalation. 2. The mucous membrane lining the nose and the throat traps more of the particulates (large and small). 3. In the trachea and bronchi, hair-like cilia sweep medium-sized particles (5 to 10 μm) upward, with a vibratory motion, into the throat where they are swallowed. Saturday, 08 February 2025 100  Pathological Effects of Dust/PM The dust particles that reach the alveoli are of smaller sizes and can be deposited on the lung surfaces through settling, impaction, Brownian motion or other processes. The body’s defence mechanism for this dust consists of phagocytes (wandering scavenger cells) called alveolar macrophages that act to engulf the invading particles and either isolate them in the lungs or transport them to the lymph node for disposal. The degree of success of this natural protection depends on the dust concentration, the composition of the dust, the person’s health status and other variables. The human body has evolved into an efficient organism designed to eliminate particles but only for levels that are found in a normal Saturday, or2025natural environment. 08 February 101  Pathological Effects of Dust/PM The defence mechanism of the respiratory system breaks down and pathological harm results when there is excessive or chemically active dust or PM or due to prolonged exposure. This leads to pathological harm known collectively as Pneumoconiosis. Examples are Silicosis - from silica or SiO2, Anthracosis - from coal dust, Baritosis - from Baryte dust, etc. Usually, other respiratory complications such as pneumonia or tuberculosis develop and pneumoconiosis aggravates the conditions and hastens death. Saturday, 08 February 2025 102  Pathological Effects of Dust/PM Saturday, 08 February 2025 103  Health Effects of PM Numerous scientific studies have linked particle pollution exposure to a variety of problems, including: 1. premature death in people with heart or lung disease 2. nonfatal heart attacks 3. irregular heartbeat 4. aggravated asthma 5. decreased lung function 6. increased respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing. People with heart or lung diseases, children, older adults, minority populations, and low socioeconomic status populations are the most likely to be affected by particle pollution exposure, either because they are more sensitive or may have higher exposures. Saturday, 08 February 2025 104  Environmental Effects of PM 1. Visual impairment 2. Depending of its chemical composition, it can; make lakes and streams acidic change the nutrient balance in coastal waters and large river basins damaging sensitive forests and farm crops affecting the diversity of ecosystems contributing to acid rain effects. 3. Material damage Saturday, 08 February 2025 105  PM Saturday, 08 February 2025 106