Environmental and Occupational Health
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During
the year under report, studies in the area of environmental and occupational
health were carried out by the Council’s National Institute of Occupational Health
(NIOH), Ahmedabad and its Regional Centres at Bangalore and Calcutta in
workers engaged in various industries such as chemicals, automobile, mining etc.
and grain and tobacco handlers as well as on air and water pollution. Assessment of the Health Status of Subjects exposed to
Chemicals/Gases evolved due to Accidental Fire in a Godown An accidental fire
broke out in April 1998 in a godown located in one of the industrial estates
of Calcutta, used by custom clearing agents for keeping the items pending
clearance of custom duties. A huge quantity of chemicals (mainly organic) was
stored in the godown. One hundred and thirteen subjects were admitted to
hospital, out of which seven died. A study was undertaken to assess the
health status of exposed subjects and follow them up to ascertain the effect
of the exposure, if any. A total of 453
exposed subjects (Community 220; Fire Brigade 203; Police 30) were clinically
examined. The predominant symptoms were headache (33.48%), vertigo (30.17%),
nausea (22.68%), irritation of mucus membrane (28.63%), eye irritation
(18.32%), skin irritation, itching and burning (6.60% to 16.74%), tingling
(11.26%), joint pain (13.21%), panic attack (5.96%) and anaemia (17.89%).
Higher values of SGOT (>40 IU/l) were also found in 50.88% and SGPT
(>40 IU/l) in 46.25% of the workers. The pulmonary function test indicated
presence of mainly restrictive impairment (Fire Brigade - 11.8%, Police -
13.8%, Community - 10.2%) with obstructive impairment being comparatively
less (3.2%). Thus, it seems that nervous system, liver and respiratory
systems are mostly affected. Considering the
nature of exposure (chemicals) it was decided to include reproductive outcome
as well as genotoxicity in the study. Suitable control subjects for each category
will also be examined. Biological Markers of Manganese Exposure and Effect in
Manganese Exposure and Effect in Manganese Miners Recent revelations
of lead toxicity even at very low levels has led to the search for suitable
alternate additive to increase the octane number of petrol. One such
compound, methylcyclo-pentadienyl manganese tricarbonyl (MMT), has been in
use in Canada and some other parts of the world. The toxic effects of
manganese at high exposure levels are well known but there are conflicting
reports on manganese toxicity at low levels of exposure. To study the effects
of manganese at low levels of exposure an environmental and medical study has
been initiated by NIOH in Collaboration with US Environmental Protection
Agency. It is planned to
measure the environmental exposure in underground manganese mines and study
the health effects of manganese at different levels of exposure using
magnetic resonance imaging (MRI) and neurobehavioral tests. During the first
phase of the programme, ambient air sampling for manganese was carried out at
different work places and in the vicinity of manganese mines at Balaghat,
M.P. The samples were collected with stationary samplers and personal
samplers for 3-8 h during underground mining and surface mining, and at one
ferro manganese plant and its vicinity. The results show
that during surface mining, the respirable dust concentrations ranged from
175.05-295.81 µg/m3 at vertical holm
shaft and from 99-456 µg/m3 at the crusher and
manual breaking and dressing units. At drilling points during underground
mining the values ranged from 172.8-614.8 µg/m3 and at the furnace units in the ferro manganese plant
it ranged from 763.1-1282.0 µg/m3. The
manganese content in the respirable dust ranged from 1.56-39.16 µg/m3 during surface mining, from 2.2-83.33 µg/m3 during underground mining, and from 33.22-75.73 µg/m3 at the ferro manganese plant. In the vicinity
(administration building, guest house, and hospital), the respirable dust
concentrations were in the range of 4.92-15.7 µg/m3 with manganese content ranging from 1.3-2.0 µg/m3. A total of 476
underground manganese miners with duration of exposure from 5 to 35 yr were
evaluated by standard medical questionnaire, computerized spirometry, chest
radiography, estimation of manganese in blood and urine and assessment of
liver function and thyroid functions. In the second phase of the study, MRI
and behavioral tests will be done on subjects selected on the basis of blood
manganese levels and clinical parameters. Effect of Lead in Children and Adolescent Development and
Puberty A long term follow
up study was undertaken in school children at Ahmedabad and Calcutta to
examine the effects of lead on adolescent development and puberty. The results
of the first phase of the study at Ahmedabad showed higher mean age, though
statistically non-significant, for various indicators of sexual maturity
rating (SMR) in children having blood lead levels higher than 10 mg/dl. During the current
year, the study was extended in 705 children (384 boys and 321 girls) of a
school situated near a lead smelter at Calcutta. Analysis of blood lead
levels showed that 69.4% of the students had levels <10µg/dl, 25.2%
between 10.0 and 14.9 µg/dl, 4.7% between 15.0 and 19.9 µg/dl and 0.7%
> 20.0 µg/dl respectively. SMR for pubic hair
in stages-1-3 did not show any significant difference in the mean age of
onset in boys with low lead levels (<10µg/dl) and high levels
(>10µg/dl). The SMR of external genitalia for boys also showed no
difference in the mean age for stages 1-4 in both the high and low lead level
groups. The mean age of
onset of menstruation was 13.91 yr and 13.58 yr for low and high blood lead
level groups respectively. The SMR of pubic hair for girls with high blood
lead levels in stages 2 and 3 was delayed as compared to that in girls with
low blood lead levels. The study is continuing. Air Pollution due to Vehicular Traffic in Major Cities/Towns of
Gujarat State Air pollution
caused by motorized vehicles was assessed to examine the air quality in eight
cities of Gujarat viz., Ahmedabad, Vadodara, Surat, Rajkot, Bhavnagar,
Jamnagar, Vapi and Mithapur. High volume samplers were used to monitor
ambient air at four typical traffic junctions in each city during peak hours.
Analysis of the samples was made for respirable particulate matter (RPM), NO2 and CO. The results show that the air quality was
found to be very poor in Ahmedabad, Vadodara, Surat and Bhavnagar. The values
for RPM, NO2 and CO were: 163-866 µg/m3, 11-105 µg/m3 and 8-33 ppm respectively in Ahmedabad; 99-3193
µg/m3, 20-113 µg/m3 and 5-35 ppm
in Vadodara; 224-1045 µg/m3, 20-156 µg/m3 and 1-9 ppm in Surat; 126-1495 µg/m3, 6-258 µg/m3 and 0-9 ppm
in Bhavnagar as compared to the air quality standards of 100 µg/m3, 80 µg/m3 and 1.75 ppm
respectively (National Air Quality Standards). The values for RPM, CO, and NO2 in the four cities were within the recommended air
quality standards. Air Pollution with respect to Levels of Polynuclear Aromatic
Hydrocarbons in High Traffic Density Areas of Bangalore City The objective of
the study was to assess the quality of air in high traffic density areas of
Bangalore city with reference to adverse health consequences among the
general population. Eight hours continuous air monitoring for total suspended
particulate matter (SPM) using high volume sampler was carried out in two
high traffic density areas covering eight locations and one residential area
(control area) covering three locations. Levels of total SPM were very high
ranging 258.93-956.44µg/m3 in high traffic density
area compared to 62.24-205.93µg/m3 in the
residential area. The samples will be analyzed for polynuclear aromatic
hydrocarbons with HPLC. The study conducted during summer season will be
followed up in the winter season as well. Development of Toxicity Testing Methods for Industrial
Effluents This
multi-institutional project is an ongoing project sponsored by Central
Pollution Control Board (CPCB), New Delhi. The aim of the project is to develop
an aquatic toxicity parameter for the industrial effluents for regulatory
purposes. During the year under report, untreated and treated industrial
effluents were collected from six dye and dye-intermediate industries
situated at Roha and Mumbai (Maharashtra). The
physico-chemical parameters for the diluent water used in the study were -
pH:7.8–8.0, water temperature: 25 ± 1°C, total hardness: 220–240mg/l,
alkalinity: 44–60mg/l and conductivity: 0.5–0.7 mS. The final
experiments were conducted using fresh water fish Brachydanio rerio in
duplicate with the control sets. The fish were exposed to a minimum of five
dilutions of the effluents for 48 h. and mortality of the fish was recorded
at intervals of two hours for 24 h. The experiments were performed along with
the reference toxicant potassium dichromate. The results show
that the value of 48 h. toxicity factor (TF) for the
reference toxicant was 100 mg/l and that of the untreated effluents was in
the range of 4-250mg/l, intermediate effluents 2-64mg/l and treated effluents
1-8mg/l. Reclamation of Vrishabavathi River Water - A Sociological Study In continuation of
our earlier study, the present investigation was aimed to assess the
knowledge gained by community regarding water pollution and recycling of
contaminated river water. A total of 1800 subjects were covered in the
questionnaire survey. Analysis of 200 questionnaires indicates that nearly
82.5% of the population did have the knowledge regarding the existing river
water pollution. It was reported that 66.6% of the population knew about
recycling of contaminated river water. Acceptance of the recycled river water
was reported by 48.5% of the population. Nearly 91% of the population did not
use this water for any purpose, while 7.5 % of the population used it for
agriculture. The study is being continued. Occupational Health Hazards among Automobile Transport Workers In seven public
automobile transport garages in Calcutta city, a large workforce of 300-2000
workers is employed. However, very little is known about the health status of
this group of workers. Therefore, a study was undertaken to assess the work
environment, personal exposure to NO2, CO, RPM, VOC
(volatile organic compound) etc. as well as health surveillance
covering work stress and postural discomfort from ergonomic point of view. Environmental
monitoring following standard methods was done using high volume sampler,
cascade impactor and personal sampler. The dust concentrations in different
areas of the garage varied between 0.131 and 0.307 mg/m3 for total dust; and 0.039 and 0.133 mg/m3 for respirable dust. Benzene soluble matter (BSM) in
different areas ranged between 0.020 and 0.036mg/m3. Concentration of trace metals like Fe, Cr, Pb, Cu, Cd
was within the prescribed limits. Pulmonary function tests (PFTs) of 181
subjects revealed restrictive (34.3%), obstructive (11.6%) and combined
(7.2%) types of impairments. On medical examination of 185 males common
symptoms were pain in abdomen (33.5%), cough (30.2%), sputum (34.05%),
breathlessness (42.8%), ringing in ears (20.0%), partial hearing loss (10.2%)
and itchiness of skin. Chronic bronchitis (23.2%), anaemia (29.2%), and
rhonchii (7.0%) were detected on examination. High blood pressure (>140/90
mm of Hg) was noted in 3.2% of the workers (drivers 3.17%; conductors 6.5%).
Systolic blood pressure >140 mm of Hg was seen in 10.8% of subjects
examined (drivers 7.9%; conductors 19.6%; mechanics 11.3%). Diastolic blood
pressure >90 mm of Hg was found in 4.3% of the subjects (drivers 4.6%;
conductors 6.96%). The workloads of drivers, conductors and mechanics were
‘moderate’ to ‘difficult’ and that of administrative staff ‘easy’ to
‘moderate’. Pain and discomfort felt in different parts of the body were also
reported (drivers 67%; conductors 60%). The study is being continued in
different garages. Prevention, Control and Treatment of Silicosis and
Silico-tuberculosis in Agate Industry A new design of
agate grinding machine has been developed. An impeller of 12 blades has been
incorporated instead of 8 blades made in the earlier design, with the
electric consumption remaining more or less the same. The installation of
this machine at Khambhat in Gujarat showed that the suction capacity of the
exhaust increased to 325 cubic feet/min (cfm) from 200 cfm, with reduction of
the respirable dust by 90% and total dust by 95% in the ambient air. Occupational Health Problems of Tobacco Harvesters and their
Prevention Occupational health
problems associated with tobacco cultivation are known as Green Tobacco Sickness
(GTS). It is a mild and acute form of nicotine toxicity that affects tobacco
workers who have direct dermal contact with tobacco plants during cultivation
and harvesting. To detect the chronic health effects of tobacco cultivation,
a specially designed questionnaire was used which included tobacco habits,
occupational and reproductive history, detailed medical examination,
examination of cardiovascular system and the eyes. Another important
objective of the study was to find out which types of gloves are acceptable
and effective in preventing the dermal absorption of nicotine with reference
to the work related symptoms and urinary excretion rate of nicotine and
cotinine amongst tobacco harvesters. Further trials are being made with
different types of hand gloves such as cotton, rubber, disposable
polyethylene, cotton with polyester, nylon (polyamine), polyester, cotton
coated on palmer side with PVC polka dots and cotton coated with natural
rubber on palmer side. A total of 685
exposed subjects (457 men and 228 women) were examined. Hypertension was
observed in 17.7% of the men and 18.0% of the women. Abnormalities of visual
acuity were noted in 26.5% of the men and 26.0% of the women. The work
related symptoms such as nausea, vomiting, giddiness, loss of appetite,
fatigue, etc. were reported by 42.7% of the men and 55.7% of the
women. Initial feedback from the workers suggested that cotton gloves were
more acceptable and comfortable in wear. Further work is in progress. Occupational Health Problems among Workers dealing with
Newspaper Refuse During the
reporting period, air-borne fungal flora obtained from three newspaper refuse
sites using Andersen-6-stage viable sampler were processed for
identification. The total number of isolates from sites I, II and III were
1.30 x 103, 1.25 x 103 and 1.41 x 103 respectively.. The number of
isolates belonging to genus Aspergillus were 19.80, 16.30 and 27.30%
respectively. Different species of Aspergillus identified
morphologically from among these isolates were 4.4, 27 and 25% for Aspergillus
flavus, 0.5, 10.6% and nil from A. parasiticus; and 2.6,
3.6 and 1.2% for A. glaucus. Other species included A. niger, A.
nidulans, A. fumigtus, A. versicolor etc. Special attention was
given on the identification of A. flavus and A. parasiticus since
these species are responsible for production of aflatoxin. Identification of
toxigenic strains of A. flavus and A. parasiticus is under
progress using qualitative media like Czapex with anisaldehyde, aflatoxin
producing ability (APA) agar medium, coconut agar media (CAM) etc. Airborne
spores of other fungal species like Cladosporium, Alterneria, Fusarium
etc. were also recovered from these sites. Inhalation of these spores is
known to produce bronchial asthma. The study is ongoing. Assessment of Occupational Health Hazards among Storage Grain
Handlers Foodgrains are
stored by different agencies like Food Corporation of India, Central
Warehousing Corporation etc. The workers are engaged in transporting
foodgrains from one place to another inside these godowns for storage and
delivery, resulting in exposure to various types of environmental
contaminants. These foodgrain handlers are exposed to respiratory hazards
from bacteria and fungal spores growing on foodgrains and the proteins of rodents,
pesticides, etc. Physical labour results in rapid and deep breathing which
makes the workers more susceptible to respiratory hazards. No comprehensive
data is available on the health status of these workers. A study was
undertaken to evaluate the health status of the grain handlers along with
measurement of fungal spores in the work environment. Measurement of grain
dust levels and evaluation of efficiency of the workers was also done. A total of 140 workers
(handling labour 46; quality control 39; ancillary 32; administrative 23)
were covered for the present phase of the study. Medical history was recorded
using standard proforma with special emphasis on occupational history and
history related to allergic symptoms relating to conjunctiva, nose, skin etc.
The symptoms recorded were redness of eyes (5.79%), eye itching (28.69%) and
watering from eyes (10.87%). Running nose, urticaria and pruritis were noted
in a relatively small number of subjects. Cough (22.46%), sputum (19.56%),
shortness of breath (35.58%), joint pain (30.43%) and low back pain (33.33%)
and itching of the skin (5.07%) were the other important complaints. High
blood pressure (>140/90 mm of Hg) was seen in 24.63% of the workers. Rhonchii
(10.14%) and crepitations (2.89%) were observed in the lungs and the PFTs
showed restrictive type of disorder in 7.8%, obstructive disorder in 7.1% and
mixed in 1.42% of the workers. The ancillary workers were found to be most
affected. Post-shift PFTs showed decrement in 53.8% subjects. Positive
broncho dilation test was noted in 4 of 5 subjects tested. Concentration of
fungal spores (Aspergillus, Cladosporium, Alternaria etc.) was
very high inside the godown. Some subjects (23.5%) reported pain and discomfort
in different parts of the body. The project is ongoing. Analysis of Industrial Accidents and Structurization of
Database A total of 593
fatal injury cases occurring in Gujarat during 1995-97 were recorded and
analysed. About 64% of the deaths occurred in the chemical, textile, shi p
breaking and engineering industries and 60% of the victims were under the age
of 30 years. Slips and fall injuries (e.g., fall on ground, fall from
height) resulting in death of about 25% of the total cases were recorded
during the study period. Machine related accidents (e.g., struck by machine,
caught in machine) represent about 19% of the cases. Data suggest that many
of the industrial injuries are preventable provided the industrial units
follow appropriate method of accident investigation and analysis. For
example, about 45% of the victims could have been saved if they were equipped
with head gear and harness belt. Detailed analysis of the data is being carried
out. Toxicity and Exposure Assessment through Microbial Screening The usual practice
of evaluation of toxicity screening in case of ‘Growth Zone Inhibition test’
using sensor organism Bacillus cereus is to express either
qualitatively or semi-quantitatively results depending upon the production of
‘halo’. Considering this, a study has been carried out to establish a
quantitative technique as an alternative to ‘Growth Zone Inhibition test’
using the same sensor organism (B. cereus). The study was initiated
with mercury (Hg2+). The toxicity of Hg2+ as worked out in ‘Growth Zone Inhibition test’ was 0.1
ppm. Determination of MIC (minimum inhibitory concentration) and MAC of Hg2+ using B. cereus as the test organism is under
progress. Identification of Carcinogen-Haemoglobin Adduct in Benzidine
exposed Workers Benzidine is a
potent carcinogen. The earlier findings on workers exposed to benzidine and
benzidine-based dyes revealed that exposure status and excretion pattern of
benzidine metabolites strongly correlated with the level of DNA-benzidine
adducts in exfoliated urothelial cells. To examine the haemoglobin-adduct
level, the blood samples were collected from 33 exposed (15 exposed to
benzidine and 18 to benzidine-based dye e.g. Direct Black 38) and 15 control
subjects matched for age, sex and socio-economic status. The analysis of
samples for acetylated benzidine-Hb adduct level is being done in
collaboration with the National Cancer Institute (NCI), USA. The findings
revealed that the Hb adducts of acetylated benzidine were non-detectable in
the control subjects. However, it was present at relatively low level in
benzidine dye exposed workers and at a very high level among benzidine
exposed workers. Comparatively, the Hb adduct content was 18 times higher in
benzidine exposed workers than the benzidine dye exposed workers. NIOH Poison Information Centre - Organophosphate (OP) Pesticide
Poisoning
Of the 377 cases of poisoning registered at the Centre, 113 (30%) were found to be of OP- poisoning. The cases of OP- poisoning were highest in the age group of 21-30 yr (46.9%) with 85% males and 15% females. Most frequent cause of poisoning was found to be suicidal (73.5%), the other causes being occupational (15%), accidental (8%), and unknown (3.5%). The exposure through oral route was found to be the most frequent (78.8%) followed by inhalation (15.9%) and combined i.e. inhalation and dermal (5.3 %). The OP-poisoning cases (44.2%) were found to be the most severe (severity score-3) requiring 8-38 days of hospitalisation. During the year, the frequency of OP poisoning was found to be higher in August and February. The farmers/farm labourers represented the highest number (42.5%). Sixty nine per cent of cases were either uneducated or had a primary level education. The above data indicate that OP insecticides continue to cause high morbidity. The commonest agents encountered were chlorpyriphos, dimethoate, phrate and monocrotophos. |
