Unit-iv unit-iv environmental Hygiene

Effects of pollutants

• In humans (atmospheric pollution due to metallic & gaseous substances is manifested by
• Bronchitis, pulmonary asthma & inflammation of upper respiratory tract
• Nitrogen oxide: Pulmonary oedema & congestion
• Sulphur oxide: Injury to mucosa
• Ozone: Effects similar to ionizing radiation
• Carbon monoxide: Depriciation of blood oxygen level following its combination with haemoglobin)
• Particulate matter have been described in detail by many workers

Pollution within animal houses

• The quality of environment within animal houses: on the health of animals & their productivity
• High densities of animals: not well ventilated lead to accumulation of excessive moisture and carbon dioxide
• Atmospheric oxygen level to 10-12% may not prove fatal to animals,
• An increase of atmospheric Carbon dioxide level to 6.0% may lead to asphyxia
• A concentration of Carbon dioxide 30% for some hours could result in death
• In horses Carbon dioxide concentration of 3-5% may cause rapid breathing
• A combination of high moisture & carbon dioxide makes animals uncomfortable & leads to a reduction in production
• Major gases: include ammonia, hydrogen sulphide & methane besides carbon dioxide
• Ammonia: irritating gas that is frequently found in the dirty farm houses
• Concentration between 0.04% and 0.5% of the gas causes much irritation of mucous membranes, asphyxia and death.
• Hydrogen sulphide (0.01 - 0.14%): irritation of eyes, throat & nose, & lung oedema
• Excessive amounts of methane may prove explosive
• Turbulence activity may also lead to production of harmful particulate pollutants

Microbial pollution of air

• A variety of microbes are carried by air
• Meteorological conditions (temperature, humidity, solar radiation)
• Amount of particulate & gaseous pollutants contribute immensely to the variation in the load and type of microbes
• Most of the atmospheric microflora emanates from the soil or due to stirring action induced by animal/human activity within the animal houses
• The microbes are adsorbed on the dust particles
• Carried over long distances under favorable weather conditions (high wind velocity) especially during outbreaks of diseases
• A large numbers of organisms (many of them pathogens) can be transmitted through air in an area
• Animals suffering from respiratory diseases discharge the microorganisms during sneezing & coughing