E 8 (A)
5. (a) How do oxides of nitrogen enter the atmosphere?
(b) What are their harmful effects ?
State the origin and health impact of smog.
7. What are the harmful effects of oxides of sulphur?
8. State the main sources and effects of carbon monoxide.
Give the mechanism of the action of carbon monoxide.
10. How can we control carbon monoxide poisoning?
Answers
ANSWERS:
5 (a) Under natural conditions, nitrogen oxides enter the atmosphere primarily as a result of lightning, which supplies enough energy to cause nitrogen and oxygen in the natural atmosphere to combine chemically.
5 (b) Environmental and health effects of nitrogen oxides
Elevated levels of nitrogen dioxide can cause damage to the human respiratory tract and increase a person's vulnerability to, and the severity of, respiratory infections and asthma. Long-term exposure to high levels of nitrogen dioxide can cause chronic lung disease.
6. Smog can cause or aggravate health problems such as asthma, emphysema, chronic bronchitis and other respiratory problems as well as eye irritation and reduced resistance to colds and lung infections. The ozone in smog also inhibits plant growth and can cause widespread damage to crops and forests.
7. Sulfur dioxide affects the respiratory system, particularly lung function, and can irritate the eyes. Sulfur dioxide irritates the respiratory tract and increases the risk of tract infections. It causes coughing, mucus secretion and aggravates conditions such as asthma and chronic bronchitis.
8. The greatest sources of CO to outdoor air are cars, trucks and other vehicles or machinery that burn fossil fuels. A variety of items in your home such as unvented kerosene and gas space heaters, leaking chimneys and furnaces, and gas stoves also release CO and can affect air quality indoors.
9. Carbon monoxide gas passes through the lungs directly into blood stream during respiration. There it combines with haemoglobin. ... It reduces the oxygen carrying capacity of the blood by an equivalent amount to the haemoglobin converted into carboxy haemoglobin.
10. (1)Know the risks of carbon monoxide.
Anything that burns a fuel — such as a furnace, fireplace or generator, gas appliance or car — produces a toxic by-product: carbon monoxide (CO).
When these devices are properly maintained and vented, this colorless, odorless gas can be effectively dispersed and channeled out of your home. If not, inhaling carbon monoxide can trigger serious health issues.
At lower concentrations, victims may experience such symptoms as a headache, dizziness, weakness, nausea, vomiting, chest pain and confusion. But at higher concentrations, CO can quickly cause a loss of consciousness, even death.
(2)Keep your vents clear.
During and after a storm, make sure nothing is obstructing the outside stack or vent for your dryer, stove, furnace and fireplace.
Take special care to prevent snow from building up and blocking these critical exits for dangerous gases.
(3)Do not run engines in a closed area.
Proper ventilation is critical to avoiding CO poisoning. So do not start a car, fire up a grill or stove, or run a generator in a closed area — like a basement or garage.
Even if you leave the garage door open, carbon monoxide gas can quickly build up to toxic levels.
(4)Schedule regular maintenance.
Make sure you rely on experts to install your fuel-burning devices and set up the appropriate venting for each device.
At least once a year, have a qualified professional inspect your fuel-burning devices to make sure they continue to operate properly.
(5)Keep fireplaces clean and well vented.
If you have a wood-burning fireplace or stove, make sure you keep it clean and that the flue is working properly.
Even if the last embers are just smoldering, keep that flue open to let the gases escape.
(6)Install CO alarms.
If you have fuel-burning appliances, a fireplace or an attached garage, consider installing these special devices in your home. You will want one on every level (including the basement), within the vicinity of each sleeping area and in other locations required by any applicable laws/building codes.
Some CO detectors can even be interconnected across your house, so that when one detects an issue, they all sound the alarm. If you do hear the CO alarm, immediately move to fresh air and call 911.
(7)Maintain your CO alarms.
Keep in mind that CO alarms do need to be maintained regularly.
Many come equipped with a battery backup to ensure uninterrupted operation, even if the power goes out. But you will need to remember to change your batteries at the frequency recommended by the manufacturer, like you do with your smoke detectors.