The lecture

1. The lecture Hygienic description of physical, chemical and biological factor of production environment

2. THE PLAN • Hazards and their prevention    • Noise, it’s influence of human organism in industry. • Vibration , it’s influence of human organism in industry. • Ultraviolet radiation • Dust, it’s influence of human organism in industry • The industrial microclimate. Exposure to heat and cold.

3. HAZARDS AND THEIR PREVENTION Various external sources, such as chemical, biological, or physical hazards, can cause work-related injury. Hazards may also result from the interaction between worker and environment; these so-called ergonomic hazards can cause physiological or psychological stress. Chemical hazards can arise from the presence of poisonous or irritating gas, mist in the workplace. Hazard elimination may require the use of alternative and less toxic materials, improved ventilation, leakage control, or protective clothing. Biological hazards arise from bacteria or viruses transmitted by animals or unclean equipment and tend to occur primarily in the food-processing industry. The source of the contamination must be eliminated or, when that is not possible, protective equipment must be worn. Common physical hazards include ambient heat, dust, noise, vibration, sudden pressure changes, radiation. Industrial safety engineers attempt to eliminate hazards at their source or to reduce their intensity. If this is impossible, workers are required to wear protective equipment. Depending on the hazard, this equipment may include safety glasses, earplugs or earmuffs, face masks, heat or radiation protection suits, boots, gloves, and helmets. To be effective, however, the protective equipment must be appropriate, properly maintained, and worn by the worker.

4. Noise, it’s influence on human organism in industry

5. Noise - "Wrong sound, in the wrong place, at the wrong time.“ Man is living in an increasingly noisy environment. The 20th century has been described as the "Century of Noise". Noise has become a very important 'stress' factor in environment of man.

6. Noise In information theory In physics In acoustics a subjective term noise is a sound vibrations of a different frequency and different loudness “white” noise consists of all audible frequencies, just as white light consists of all visible frequencies the term designates a signal that contains no information Noise is referring to any unwanted sound

7. Properties of Noise 1. FREQUENCY Human ear can hear frequencies from 16 – 20 000 Hz. Infra audible : Sounds below 16 Hz Ultra sonic : Sounds above 20,000 Hz On frequency distinguish noise of low frequency (16… 350 Hz), middle-frequency (350… 800 Hz) and high frequency (more than 800 Hz). 2. LOUDNESS It is measured in decibels (dB). It depends upon amplitude of vibrations, which initiated noise. A daily exposure up to 85 dB is about the limit people can tolerate without substantial damage to their hearing.

8. Sound intensities are measured in decibels (dB). For example, the intensity at the threshold of hearing is 0 dB, the intensity of whispering is typically about 10 dB, and the intensity of rustling leaves reaches almost 20 dB. Sound intensities are arranged on a logarithmic scale, which means that an increase of 10 dB corresponds to an increase in intensity by a factor of 10. Thus, rustling leaves are about 10 times louder than whispering. The decibel scale is logarithmic and climbs steeply: An increase of about three decibels is a doubling of sound volume. In the wilderness, a typical sound level would be 35 dB. Speech runs 65 to 70 dB; heavy traffic generates 90 dB. By 140 dB, sound becomes painful to the human ear, but ill effects, including hearing loss, set in at much lower levels.

9. Acceptable Noise Levels RESIDENTIAL: Bed room - 25 dB Living room - 40 dB COMMERCIAL : Office - 35-45 dB Conference - 40-45 dB Restaurants - 40-60 dB INDUSTRIAL : Workshop - 40-60 dB Laboratory - 40-50 dB EDUCATIONAL: Class room - 30-40 dB Library - 35-40 dB HOSPITALS: Wards - 20-35 dB (45dB )

10. The most significant health problem caused by noise pollution is hearing loss . Any noise appreciably louder than talking can damage the delicate hair cells in the cochlea, the structure in the inner ear that converts sound waves into auditory nerve signals. The initial damage to the cochlea may be temporary, but with repeated exposure, the damage becomes permanent. But even sound levels of only 85 decibels will cause some hearing loss after prolonged exposure. In addition to deafness, many people with damaged ears are afflicted with tinnitus, or ringing in the ears.

11. Deafness, most simply defined as an inability to hear. This definition, however, gives no real impression of how deafness affects function in society for the hearing-impaired person. Four types of hearing loss may be described. The first, conductive hearing loss, is caused by diseases or obstruction in the outer or middle ear and usually is not severe. A person with a conductive hearing loss generally can be helped by a hearing aid. Often conductive hearing losses can also be corrected through surgical or medical treatment. The second kind of deafness, sensorineural hearing loss, results from damage to the sensory hair cells or the nerves of the inner ear and can range in severity from mild to profound deafness. Such loss occurs in certain sound frequencies more than in others, resulting in distorted sound perceptions even when the sound level is amplified. A hearing aid may not help a person with a sensorineural loss. The third kind, mixed hearing loss, is caused by problems in both the outer or middle ear and the inner ear. Finally, central hearing loss is the result of damage to or impairment of the nerves or nuclei of the central nervous system. Continuous or frequent exposure to noise levels above 85 dB can cause a progressive and eventually severe sensorineural hearing loss.

12. Decibel Scale

13. Industrial Noise A number of industrial operations generate noise. Stamping metal into auto fenders, punching holes into metal plates, riveting plates together, and crashing different materials all produce impact noise, and grinding and drilling metal produce continuous noise. Rapid air motion caused by jets of air, blowers, and fans, and vibration of equipment also cause noise. Although industrial noise mainly affects workers in the industry, some of this noise also reaches nearby homes.

14. Most hearing loss occurs in workplaces, where workers may be unable to avoid unhealthy noise, and where exposure may continue for years. Factory workers musicians firefighters construction workers police officers farmers military personnel

15. EFFECTS OF NOISE EXPOSURE • The effects of noise exposure are of two types : • auditory and non-auditory. • 1. AUDITORY EFFECTS • Auditory fatigue : It appears in the 90dB region and greatest at 4000 Hz. It may be associated with whistling & buzzing. • Deafness : Temporary deafness appears in frequency range of 4,000-6000 Hz. It disappears after sometime. • Permanent deafness appears after repeated or continuous exposure to noise around 100 dB. Exposure to noise above 160 dB may rupture tympanic membrane

16. 2. NON - AUDITORY EFFECTS: a) Interference with speech: Noise interferes with speech communication. The frequencies causing most disturbances to speech lie in 300-500 Hz range. b)Annoyance: This is primarily a psychological response. c)Efficiency of work: Efficiency of work decreases because there is loss of concentration due to noise. d)Physiological changes: A number of physiological changes occur due to noise, they are : •         Increase in blood pressure •Increasein intracranial pressure •Increase in heart rate •Increasein breathing rate •         Increased sweating e)General effects Nausea, vomiting, giddiness and fatigue may also occur. Sleep is also disturbed by noise.

17. Noise makes conversation difficult, interferes with some kinds of work, headache, tiredness, loss of memory and appetite, and disturbs sleep. Noisy disease is a general illness of an organism with such symptoms as damage of hearing organ cardiovascular problems, high blood pressure nervous disorders

18. Noise Control Methods Level of noise can be controlled and changed in some ways. Substitution of a quieter machine design, process, or material may be an easy and effective means of eliminating or reducing a noise problem. This principle can be or has been applied in several ways. For example, a low-speed propeller fan makes less noise than a high speed one, and a squirrel cage blower makes less noise than a propeller-type fan. Installing devices that resist motion and thereby damp vibration or using stiffer materials that resist vibration, can reduce noise from vibrating surfaces. Forces that cause vibration can sometimes be isolated by mounting the equipment on springs or resilient materials such as rubber and by using flexible connections. Jet exhausts can be modified to produce less air turbulence, and mufflers reduce noise from engine and air exhausts. If noise cannot be reduced to acceptable levels in industry, personal protection or special design considerations may be necessary. Fitted earplugs sometimes protect the ear more effectively, but the visibility of earmuffs makes their use easier to supervise. Workers may also be shielded by enclosing or partly enclosing the noisy operations. If reverberation is a problem, surfaces can be treated with sound-absorbing materials that do not reflect sound. In offices and homes, rugs, curtains, and acoustical ceiling materials are used to absorb sound. Because heating and air conditioning ducts provide a part for sound transmission, they can be lined with sound-absorbing material or baffled to reduce noise.

19. NOISE CONTROL While noise cannot be totally eliminated, much can be done to reduce it. 1. Control at source : This can be achieved by segregating noisy machines, application of noise mufflers, etc. 2.Control of transmission : This may be achieved by building enclosures and covering room walls with absorbing material. 3.Protection of exposed people : Exposed people must use earplugs. They must be regularly checked and moved from noisy place to quiet place.

20. Vibration , it’s influence of human organism in industry.

21. Vibration is characterized by: • frequency (Hz) - (one oscillation for one second) • amplitude (m) - (maximal deviation of body from position of stable balance) • Its derivatives on time – • vibrospeed (m/sec) • vibroacceleration (m /sec2) As criteria for hygienic estimation and normalizations of vibration are applied vibrospeed or vibroacceleration as changes in an organism under the influence of vibration depend on the quantity of energy of the fluctuations transmitted to an organism which, in turn, is proportional to a square of oscillatory speed or oscillatory acceleration.

22. Vibration, especially in the frequency range 10-500 Hz, may be encountered in work with pneumatic tools, such as drills, hammers, and chisels, in mines, quarries, foundries or the machine industry, or with other machines, such as those used in the shoe industry, and motor saws in forestry.

23. Vibration local is transferred to hands of the working at contact to the vibrating tool or the equipment general Is transferring on a body of the sitting or worth person through basic surfaces (a seat, a floor, a working platform)

24. Vibration usually affects the hands and arms. After some months or years of exposure, the fine blood vessels of the fingers become increasingly sensitive to spasm, especially after exposure to the cold or to vibration (white fingers). Exposure to vibration may also produce injuries of the joints of the hands, elbows and shoulders. Such symptoms may be very common, e.g., among forestry workers.

25. Vibration is constant (vibrospeed changes less than 6 dB for 1 minute) changeable(changes of the vibrospeed more than 6 dB for 1 minute) To changeable vibrations concern: varying in time (the level of the vibrospeed continuously changes) faltering (contact of the operator to vibration interrupts and makes more than 1sec) pulse (one or several vibrating influences by duration less than 1 seс)

26. The prevention of Vibration • The prevention measures of decline of influencing of vibration on an organism include: • technological processes (automation of remote control, creation of machines with vibroisolation facilities) • rational regime of labour (time of contact with vibration makes a 20-30% working change, 2 breaks for active rest) • individual facilities of protection (specific gloves and shoes) • periodic medical control

27. Ultraviolet radiation In industry workers are affected by ultraviolet rays with the length less than 280 nm. Occupational exposure to ultraviolet radiation occurs mainly in arc welding. Such radiation mainly affects the eyes, causing intense conjunctivitis and keratitis (welder's flash.) Symptoms are redness of the eyes and pain; these usually disappear in a few days. The welder himself is usually well protected against radiation from his own work. The worker affected by welder's flash will therefore often be found to have been standing next to a welder, and to have been wearing goggles that do not protect the sides of the eyes. No permanent disability appears to result from this occupational disease.

28. Dust, it’s influence of human organism in industry

29. Dusts are solid particles generated by handling, crushing, grinding, and disintegrating organic and inorganic materials, such as rocks, ore, metal, coal, wood, and grains. The exposure of man to dusts can lead to a wide variety of respiratory diseases, including pulmonary fibrosis, obstructive lung disease, allergy and lung cancer. Toxic dusts may produce systemic poisoning after inhalation, or act as skin irritants to produce dermatoses, allergic reactions and cancer.

30. Classification of a dust I. For the origin the dust is divided into three groups: 1) Organic (-Vegetative: wood, plans, tobacco, cotton, Cane fibre -Animal: Hay or grain dust);   2) Inorganic (-Mineral: Quartz, Coal, Silica, Asbestos, - Metal: Iron and other ); 3) Mixed (artificial, plastic). II. Froom dispersing into two groups:   1) Aerosol of disintegration 2) Aerosol of condensation III. For the size: 1)  Visible – the size of speck of dust is more than 10 micrometer, 2)  Microscopic – the size is 10 - 0,25 micrometer, 3) Ultramicroscopic – the size is less than 0,25 micrometer

31. Dust influences on: - System of breath and causes such specific illness -pneumoconiosis, pneumonias, chronic bronchitis, and not specific illness such us: cancer, tuberculoses; -        - On skin; - On eyes.

32. The hazardous effects of dusts on lungs depends upon a number of factors, such as a) Chemical composition b) Size of particle c) Concentration of dust in air. d) Period of exposure e) Health status of workers

33. Pneumoconiosis (plural, pneumoconioses), a general term for any one of several lung diseases caused by breathing dust from industrial occupations like coal mining, sand blasting, and stone cutting.Years of continual exposure to industrial dust can cause the formation of spots (macules), lumps (nodules), or fibrous growths in lung tissue, causing permanent damage or destruction of these tissues. Smoking can complicate or worsen the conditions. Symptoms of the disease include shortness of breath, labored breathing, coughing, and production of phlegm.

34. Forms of pneumoconioses are: — Anthracosis -Coal dust — Silicosis - Silica — Asbestosis - Asbestos — Siderosis – Iron — Bagassosis - Cane fibre --Byssinosis - Cotton dust — Tobacossis - Tobacco — Farmer's lung - Hay or grain dust

35. Silicosis Free silica (SiO2) in the form of quartz, tridymite, or cristobalite, can cause silicosis, whereas silicates do not usually present a significant health hazard. Drilling, crushing, grinding or handling quartz sand produces quartz dust. Occupational exposure occurs in mines and quarries, not only where quartz is mined but also in metal mines where the rock between the veins of ore contains free silica. Exposure may also occur in factories where quartz sand is used, e.g., in steel works and iron foundries, and in the ceramics and glass industries.

36. Dust enters the body by inhalation. Particles larger than 5 microns in size are generally deposited in the upper respiratory tract and bronchi, and are gradually removed by the ciliary’s epithelium (lung clearance). Smaller particles are deposited in the alveoli of the lungs and then gradually transported to the corresponding lymph nodes. The proportion of the dust that remains in the lungs does so for life, since quartz particles are practically insoluble; connective tissue is then formed around the particles so that nodules are produced. The nodules may gradually aggregate and massive pulmonary fibroses may develop later and progress over a number of years, leading to emphysema with gradual impairment of lung function. Subjective symptoms, which develop rather late, include cough and shortness of breath (dyspnoea) at effort. Silicosis is often combined with tuberculosis. The disease is gradually progressive and death occurs from right heart failure or from pulmonary tuberculosis. It usually takes 15 to 20 years of exposure before symptoms develop. Unprotected workers in occupations with intense exposure to silica, such as sandblasting in confined spaces, tunneling through rock with a high quartz content, and manufacturing abrasive soaps, may develop silicosis in less than a year.

37. Anthracosis Coal worker's pneumoconiosis, also known as black lung disease or anthracosis, is caused by inhaling coal dust for prolonged periods, usually at least 10 years. Coal worker's pneumoconiosis is much more common in miners of anthracite coal than in miners of bituminous coal.

38. These diseases (Silicosis and anthracosis) are diagnosed when small, irregular, opaque areas are seen on X-ray and people have a history of expo­sure to coal dust or silica. With long-term exposure, these irregular areas become larger and combine into more regular, small, rounded nodules. However, both coal worker's pneumoconiosis and silicosis may develop into progressive massive fibrosis, also called complicated pneumoconiosis. Only a small percentage of those with coal worker's pneumoconiosis develop massive fibrosis. The mechanism that causes it is unknown. Those with silicosis, however, are likely to develop progressive massive fibrosis. There is no specific treatment for either of these diseases.

39. Prevention Prevention is the best course of action. Wear a dust mask and take other steps to prevent exposure to the dust if man is working in an occupation that puts at risk of developing one of these diseases. In addition, do not smoke.

40. ASBESTOS • Symptoms: • •   Chest pain • •   Shortness of breath • •  Decreased exercise tolerance • Cough

41. Asbestos is a mixture of magnesium and iron silicates in fibrous form. It appears as dust in the form of fine fibres in the air.Asbestos is a general name for a class of natural fibrous hydrated silicates of different chemical composition and with different physical properties, such as range of fibre diameter, flexibility, tensile strength, and surface properties. They consist of 40-60 % of silica (SiO2) in combination with oxides of iron, magnesium, and other metals. The most important forms are chrysotile (white asbestos, which accounts for 95 % of world production) and the amphiboles, which occur in different varieties, e.g., crocidolite (blue), amosite (brown), and anthophyllite (white).

42. Occupational exposure occurs in asbestos mines and wherever absestos or asbestos products are used, for instance, in handling asbestos-cement products used in the building industry (roofing sheets, wallboard and pipes). Exposure may also occur in the textile industry in the manufacture of fireproof materials, such as asbestos clothes or brake linings for motor vehicles. Asbestos is also used for insulation and fire protection.

43. There has been a very rapid expansion in the use of asbestos. In 1924 the world production was 300 000 tons of chrysotile, 5000 tons of crocidolite, and 3000 tons of amosite; the corresponding figures in 1964 were 3 000 000, 120 000, and 80 000 tons respectively. As there are over a thousand uses of asbestos, the number of occupations in which exposure may occur and the number of possible sources of exposure of the general population are also very large. Asbestos fibres can become airborne during road building, soil tilling, and by erosion and weathering. Air pollution may also result from mining and milling, transportation of asbestos ore and asbestos-containing products, and ventilation of asbestos manufacturing plants. Asbestos cement, floor tiles, heat and electric wire insulation, brake linings, asbestos cloth and paper, pipe and furnace fittings, sprayed fireproofing materials, and paint filters represent sources of environmental pollution of varying importance. Asbestos may be found also in water (asbestos pipes) and in beverages such as beer (asbestos filters). A study of river water showed that asbestos fibers were almost universally present, although in small amounts .

44. The evidence for non-occupational exposure to asbestos is derived from three sources : • (1) Asbestos fibres have been demonstrated in the lungs of persons not occupationally exposed . • (2) Asbestos fibres have been demonstrated in ambient air . • In a few geographical areas, pathological changes regarded as indicating a reaction to asbestos—such as pleural calcification—have been identified in persons with no obvious occupational exposure . • Such evidence was obtained in Finland in the vicinity of asbestos mines; in the German near an asbestos factory; in Bulgaria in rural populations in relation to asbestos in the soil; and in rural districts of Czechoslovakia .

45. Different types of asbestos do not seem to be equally hazardous, and in considering the effects of exposure it is essential to know both the type of asbestos and the circumstances of exposure. It has also been pointed out that the biological effects of asbestos fibres may depend not only on the physical and chemical properties of the fibres themselves, but also on their contamination with other chemical substances and on the smoking habits of the exposed population groups.

46. Asbestosis is an occupational disease. Asbestosis has been produced experimentally in various animal species such as rats, rabbits, and monkeys. Using quantitative inhalation techniques, have shown that chrysotile produces less fibrosis than an equal dose of amosite or crocidolite; this appears to be due to different rates of elimination. The importance of particle length is not yet quite clear, but some authors have shown that in several species fibrosis of the lung is produced by fine particles or very short fibres.

47. The association of lung cancer with asbestos exposure was first suggested by Lynch & Smith but convincing epidemiological evidence was not provided until Merewether reported 31 cancers of the lung among 235 persons who died of occupationally acquired asbestosis in the United Kingdom between 1924 and 1946. Further studies in many countries, including the United Kingdom, the USA, South Africa, Canada, Finland, Australia, the USSR, and Italy have confirmed the association between occupational exposure to asbestos and an excess incidence of bronchogenic cancer. It is difficult to establish whether an increased rate of lung cancer may result from exposures that are insufficient to cause asbestosis, but it is certain that the risk of bronchial cancer is exceptionally high if occupational exposure to asbestos is combined with cigarette smoking . There is no evidence so far that non-occupational exposure to asbestos may increase the risk of lung cancer.

48. Asbestos exposure may cause asbestosis(a form of interstitial fibrosis or pneumoconiosis), mesothelioma(a cancer of the lining of the lung or abdomen), or lung cancer.

49. Pulmonary asbestosis may result when the fibers accumulate around bronchioles, the smallest air passageways. Lungs react to the fibers by covering them, forming small masses of scar tissue. Symptoms appear when the scar tissue causes your lungs to lose their elasticity. The first symptom of asbestosis may be the gradual appearance of shortness of breath on exertion. Another result of prolonged exposure to asbestos may be the development of pleural plaques around lungs. These areas of thickening of the pleura, the double membrane that surrounds your lungs, usually occur along the lower part of the chest wall or near the diaphragm. The presence of pleural plaques is strong evidence that you have been exposed to asbestos but does not mean that your lungs are impaired unless you have other symptoms or signs.

50. Mesotheliomas, malignant tumors arising from the pleura, are a relatively rare type of cancer. Mesotheliomas may develop 20 to 40 years after the exposure to asbestos fibers and can occur even if the exposure was for only 1 or 2 years or even less. Many persons with mesothelioma have no history of exposure to asbestos. The symptoms include chest pain, gradual appearance of shortness of breath, and weight loss. In about half of those with mesothelioma, the disease spreads, producing tumors in other parts of the body. In other cases, the tumors are limited to the chest. Pleural effusion, the buildup of fluid between the two layers of the pleural membrane, often contributes to shortness of breath and chest pain. The disease usually is fatal within 8 to 14 months; 75 percent of patients with mesothelioma die within a year after diagnosis.