RESEARCH

• General
• Screening & Diagnosis
• Prevention Measures
• Treatment Techniques & Results
• Environment & Product Monitoring
• National Policy,Standards, Legislation & Enforcement
• Studies & Findings
• Country Projects & Programs
• New Ideas & Recommendations
• Publications
• Unpublished Work

Environment & Product Monitoring

EMPIRICAL EVIDENCE ON LEAD SOURCES AND PATHWAYS IN INDIA

Some Identified Sources of Lead in India

Dr. S.K. Tandon

Introduction

The sources of lead in India from the viewpoint of health hazards may be in the following order of importance:

l . Automobile exhaust from leaded gasoline

2. Lead-battery recycling plants

3. Lead smelting as in silver refining for jewelry & articles works.

4. Lead based pigments & paints

5. Printing press

6. Ceramic pottery glazes

7. Lead containing cosmetics & folk medicines

Table 1 includes the results of a study on the applications of lead in India.

Specific Occupational Hazards of Lead Exposure in India

Lead poisoning in India has been mainly from printing press ¹, pigment manufacturing industry ², electrical accumulator industry ^3, and silver refining industry ⁴. Lead poisoning in adults and children is attributed to lead fumes and lead oxide dust emanating during process of extraction of gold and silver from waste.

In 8 out of 9 male workers 25-65 years involved in silver purification by heating impure silver waste with lead scraps at high temperature, an average blood lead of 120.8 m g/dl 40-210m g/dl was observed. Other biochemical and clinical symptoms confirmed lead poisoning. The work atmosphere was filled with lead and lead oxide fumes lasting for 4-6 h/day/week. The vapors also condensed on workers skin, hair, contaminating their clothing, food and drinking water ⁵.

A silver jewelry worker with blood lead of 210 m g/dl, a printing press worker of 43 m g/dl and a manager in metal division of a steel factory of 84 m g/dl were found suffering from lead poisoning with clinical symptoms such as blue lining of gum, abdominal colic, wrist drop and fatigue. Treatment with BAL 100 mg. intramuscularly daily for 5 days showed increased excretion of lead and reversal of lead sensitive parameters. Blood lead levels lowered to 67, 17 and 36 m g/dl respectively⁶.

Seven male silver jewelry workers, 25-70 years, approached Neurology Department, K.G. Medical College, Lucknow, with acute abdominal colic (7) , sweet taste of mouth (5) , constipation (5) , anorexia (2) and giddiness (2) . Clinical examination of workers showed pallor (6) , blue lining of gum (3) and motor neuropathy (1) . They worked 8h/day/week and reported to take no precaution against lead or lead oxide fumes. The duration of exposure at work ranged 12-50 years. The average blood lead was 113:4 m g/dl 71-208 . The hematological and urinalysis confirmed lead poisoning. They were withdrawn from work and treated with oral D-Penicillamine 3.5-4.5 g/day for 7 days. The lead sensitive parameters after cessation of therapy showed significant improvement

In a silver jewelry industry at Hupri Kolhapur 105 workers were engaged in different workshops:

1. Silver refining from waste by lead -smelting & alloying
2. Rolling & milling of silver wire & pieces
3. Die cutting & designing of silver jewelry
4. Assembling of silver pieces & soldering
5. Polishing & plating of silver jewelry

Twenty three workers with blood lead 60 + 36 m g/dl against control 22 ± 9m g/dl were found to suffer from lead poisoning based on biochemical parameters and clinical symptoms. Nineteen of them were working in smelting and alloying with air lead 248+43 g/m3, and assembling and soldering air lead 348± 36± g/m3 in workshops .

In India, secondary lead production has increased from 14,100 to 29,000 tonne, in 1990-97, as industrial infrastructure and automotive market expanded. Lead acid batteries constitute 75% of lead consumption. There are 7 medium secondary Iead plants, 40 small operations with 15,000T/year and over 250 tiny backyard plants with 25,000T/year. Source of lead in these plants is scrap batteries. Major problem in India is that of low technology and pollution by smaller secondary plants.

Secondary lead refining is by batch processing based on traditional pyrometallurgical method. Batch refining is carried out in hemispherical vessels usually stirred to mix reactants and oxidation is done by injecting air or oxygen enriched air. Metal is held molten while reaction products float outside and are recovered from surface. In backyard smelters, lead scraps and wastes are smelted first in open receptacles and then refined to pure lead and also in manufacture of lead alloys. The backyard smelters, dispersed widely and have no pollution control system ¹⁰. Figure 1 illustrates the flow sheet of lead battery scrap processing plant.

According to another lecture at National Conference on Lead & Zinc Recycling, New Delhi, Dec. 17&18, 1998 Thadani, B.C, only 45% lead battery requirement in India is met by 7 organized battery manufacturers, and the remaining by generally unorganized 250 small scale battery units and 4,500 battery assembling and reconditioning workshops. Most of the spent batteries are either taken by small scale assemblers or collected and processed by backyard smelters which are the sources of lead pollution. The methodical collection and processing of spent batteries should be adopted in India.

About 80% of lead used in lead acid batteries are available for re-use by processing. As automobiles are growing rapidly in developing countries of Asia, more battery scrap will be available for recycling. This is of importance in developing economies, not only to meet growing lead demand but also to ensure that spent batteries are not thrown away to avoid environmental problems. The production of secondary lead has exceeded that of primary since 1991. Secondary lead is refined lead and lead alloys from scrap materials such as lead-acid batteries, lead sheet strip pipes, cable sheathing.

Every country is developing recycling activities. In 1995, European industry was recycling over 10 million vehicles and 45-48 million lead-acid batteries. In 1997, Western world average lead ratio between production of refined lead & lead alloys from scrap 2,929 mt. and refined lead production 4,956 mt amounted to 59% and for USA to 76%. These activities are increasing in Asia .

Priority Areas for Investigation in India

1. Automobile exhaust from leaded gasoline
2. Lead battery recycling activities
3. Lead smelting for silver purification for jewellery & articles
4. Childhood lead poisoning from lead based pigments & paints, soil etc. 1-6 years

Organizations Engaged in such Work in India

1. Industrial Toxicology Research Center, Lucknow - Dr. S.K. Tandon.
2. Department of Neurology, King George's Medical College, Lucknow - Prof D. Nag.
3. Department of Biochemistry and Biophysics, St. Jones, Medical College, Bangalore - Dr. T. Venkatesh.
4. National Institute of Occupational Health, ICMR Ahemdabad - Dr. H.N. Saiyed/Dr. D.J. Parikh.
5. National Institute of Nutrition ICMR Hyderbad - Dr. K. Krishnaswamy.

The head of institution may be requested for Annual Reports & literature available and their expertise in various aspects of lead poisoning, prevention and treatment.

There is ample scope for cooperative work among organizations in India. The work may be allotted according to their infrastructure facilities and expertise. There should be a nodal institution to coordinate the program.

References

1. Chakraborty, M.K. et al., A study of occupational lead hazard in select Indian industries, Ind. J. Med. Res. 38, 429-56, 1950
2. Sabnis, C.V., Evaluation of lead, hazard in a pigment manufacturing concern, Ind. J. Med. Res. 4053-61, 1952
3. Ghosh, P.K. et al., A study of occupational lead hazard in two electrical accumulator industries, Ind. Med. Gaz. 87, 114-17, 1952
4. Joshua G.E. et al. Lead poisoning in a family of 18 members in Vellore town, Ind. J. Med. Res. 59, 1496-507, 1971
5. Behari, J.R. et al., Lead poisoning among Indian silver jewelry makers, Ann. Occup. Hyg. 27, 107-09, 1983
6. Flora S.J.S. et al., BAL therapy in human lead poisoning, Ind. J. Med. Sci. 39, 187-91, 1985 .
7. Kachru, D.N. et al., Occupational lead poisoning among silver jewelry workers, Ind. J. Med. Sci. 43, 89-91, 1989 .
8. Flora, S.J.S et al., Plumbism" among Indian silver jewelry industry workers, J. Environ. Sci. Hlth. A 25, 105-13,1990 .
9. Gill, ILZIC quarterly, 5 2 , 1-6, 1997 .

Background of Lead Sources in India

Dr. S. J. S. Flora

Lead is a widespread constituent of the earth's crust. It has always been present in soils in rivers, lakes and seas, in the air, following the burning of wood and coal, and in plants, both edible and inedible. Throughout history, lead has been well known and extensively used by mankind and so, over a period of centuries, it has been dispersed by man into the environment. There are many reasons for the vast commercial utilization of lead. Some of the important properties include low melting points, easy workability, ability to form carbon metal compounds, favorable oxidation-reduction potential useful for electrochemical application, formation of crystal desirable in pigment, relatively low cost and easy recyclability. At present one of the major uses of lead is in the Lead Acid Storage manufacturing industries which account for about 50% of the refined lead consumption, while production of tetraethyl lead as an automobile additive to reduce engine knock accounts for almost 10% of the consumption.

Refined lead is produced from both primary and secondary sources. Primary lead is that produced from mined ores, whilst secondary lead results from recycling materials such as battery plates, lead pipes etc. However, due to its high degree of corrosion resistance and insolubility, lead is less readily released into the environment than most other metals. Various sources are responsible for the excessive presence of lead in the Indian environment. Among these, vehicular emission and wastewater streams from battery industries contribute to the problem to a greater extent and therefore require priority attention. In India, mining, smelting and refining of lead as well as the manufacture and use of lead based products also release lead into the environment. Leaded paints have also been an important local source and many cases of lead poisoning among children have been traced to peeled paints chips from toys, furniture bearing lead paints, printed papers etc.

India was centuries ahead of Western Europe in the industrial production of lead. This has been reaffirmed by excavation work carried out by the British Museum, Baroda University and Hindustan Zinc limited. Zawar mines are the "earliest dated Lead-zinc mines in the world". The commercial exploitation of Zawar mines was resumed in the 20^th century by Metal Corporation of lndia (MCI). MCI had also put up a lead smelter in Tundoo, Bihar in the year 1942 to treat lead concentrate. Hindustan Zinc Limited (HZL) was incorporated in 1966. Starting with one mine producing 500 TPD lead zinc ore and a 3600 TPA Lead Smelter in 1966, HZA has come a long way and today operates nearly six lead zinc mines. India's total identified lead ore reserves are estimated to be around 383 million tonnes (as of 1989) with Rajasthan having a major share. Andhra Pradesh, Gujrat, Orissa, Bihar and West Bengal also have some reserves. Total production of lead concentrates in India was 17,000 tonnes in 1980 and 89,000 tonnes in 1989. India has a very small share in world market for refined lead production which was only 0.5% in 1986. Production of primary lead metal follows the sinister roast, blast furnace reduction fire refining process using sulphide lead concentrates. Beside lead mines and petroleum consumption, silver jewellery industry in India too contributes a great deal in the incidence of lead poisoning. The exposure to lead fumes during purification of silver involving heating of impure silver waste together with lead at high temperature is quite prevalent amongst silver jewellery workers in India. Several chronic cases of occupational lead poisoning in adults and children have been attributed to lead fumes and lead oxide dust emanated during extraction of gold and silver from silver jewelry waste. Lead acid storage battery currently accounts for almost 50% of the consumption of lead in the world. The processes involved in the lead acid battery manufacture expose the workmen to varying degrees of lead in air in the form of fume or particulate leading to absorption and eventual poisoning in some cases. A typical uncontrolled emission factor is estimated to be 8-8.5 kg of lead per thousand batteries, 80% of which can be checked by well-planned control measures.

Environmental impacts from industries in general consist of degradation of Eco-system, pollution of air and water, and socio-economic change. Production of lead can also have similar impact. In India, permissible limit of lead in effluent discharged from industries as per standard laid down by Central and State Pollution Controls Board is 0.1 milligram/litre. Portable water having concentration about O.l mg/litre is considered unsafe and should be rejected for human consumption. WHO has set 0.05 mg/litre as a guideline value for lead in drinking water.

Recommendations/Priority Areas:

1. Regular biological monitoring for lead in the workers of lead based industries should be done.
2. It is important to identify the laboratories in India where facilities to carry out complete and specific test for lead poisoning can be done. Presently, there are only few laboratories where such facilities are available.
3. Beside screening of subjects who are handling lead there are certain other groups of population which are equally susceptible like cab/taxi drivers, traffic policemen, printing press workers, population consuming illicit liquor etc., who also require extensive screening.
4. One of the major priority areas for researchers in India is the development of a safe, effective and specific drug. It is indeed unfortunate that there are only a couple of laboratories in India, which are making efforts in this direction.

Suggested Reading:

1. Flora SJS, Singh S, Tandon SK. Plumbism among silver jewellery industry workers, J/ Environ. Sci. Health A25, 105-113, 1990.

2. Flora SJS. Lead in the environment: health effects and management. Ann Natl Acad Med Sci., 25, 271-277, 1989.

3. "Comprehensive Survey of the Battery Industries in India", CPCB, 1993

4. The Environmental (Protection) Act, 1986 &Rules, Govt of India

Health Risk Assessment forLead Exposure in Chennai, India

Dr. Kalpana Balakrishnan

Introduction

Health risk assessment procedures originally developed by the USEPA have been used extensively throughout the world for quantification of health risks associated with environmental exposures to a variety of pollutants. However, the risk assessment framework is yet to be systematically applied for addressing health concerns in India. While a lot of exposure information is available, this has not been integrated into a quantitative dose response assessment and therefore the risk characterization has remained qualitative in most Indian studies.

The present study represents initial efforts to quantify health risks from exposure to lead in the Chennai metropolitan area using the quantitative risk assessment framework. Preliminary exposure information on humans including children has been collected and efforts to assess the relative contributions of various pathways are in progress. Although the exposure information is inadequate at present and needs to be significantly enhanced before drawing definitive conclusions for the Chennai area, the results have shown that health effects likely to result from the current exposures are quite severe. They can have substantial economic costs both to the individual and the society at large. The study, once completed, can lay down the groundwork for performing a rigorous cost-benefit analyses for various strategies aimed at exposure reduction.

Methodology

Blood lead levels were determined for 151 outpatients (of which there were 39 children below the age of 5) of SRMC hospital, and they were analysed through Atomic Absorption spectrophotometry. Background information on location of their residences/ schools, occupation and other socioeconomic details were collected through a questionnaire.

Information on occupational exposures was also collected for 36 tannery workers who were involved in machine shop operations such as soldering and painting. Worker exposures were assessed through air sampling using personal samplers attached to filter cassettes (MOSH procedure 8003) and through collection of blood samples.

Information on levels in ambient air and water was collected from previously published studies. Information on levels in soil and food and lead content in gasoline is being collected. Similarly data on industrial emissions is also being collected with the aid of the Tamil Nadu State Pollution Control Board.

Calculation of health risks were done using published dose - response relationships for infant mortality (CDC, 1991 ), IQ decrements (Schwartz, 1993) and elevation of blood pressure (Pirkle et. a1.1985 and Schwartz 1988).

Results

a) Blood lead levels

The mean blood lead level for outpatients at SRMC hospital most of whom were residents of neighbouring localities in the city was 16.2 ug/dl ± 4.2 ug/dl. The levels in children alone averaged around 18.8ug/dl. The levels in workers with occupational exposures were around 26.8 ug/dl ± 5.7ug/dl.

b) Assessment of contributions from various environment pathways

The average ambient air concentrations lead concentrations were reported to be in the range of 0.1 - 0.2 ug/m 3 (NEERI, 1992). The predicted contribution to blood lead levels using a slope factor of 1.6 (ug/dl per unit concentration) according to references OECD, 1993 and USEPA, 1986 would be less than 1 ug/dl.

The levels in water, determined through limited analysis of water samples from neighboring localities was found to be in the range of 60 - 100 ug/1. Using a slope factor of 0.06(ug/dl per unit concentration) ( Marcus 1989), the contribution to blood lead levels would be in the range of 3- 6 ug/dl.

Information on levels in food and soil are currently being gathered and therefore their contributions could not be ascertained.

c) Health risks from lead in Chennai

present study, the results are in broad agreement with levels reported in various other studies carried out within India. Further, although contributions form individual pathways has not been estimated, health risks for lead can still be calculated as they are based on the use blood lead levels as the bio-marker for all environmental exposures.

Assuming a decrease of 0.25 IQ points for 1 ug/dl increase in blood lead ( Schwartz 1993) and assuming that the mean levels in children are around l8ug/dl, children would have a mean IQ of 3.25 less than their counterparts in the developed world with blood lead levels of 5ug/dl. Although there is considerable variation in estimates, the cost associated with such a decrement is substantial.

The crude birth rate in the Chennai metro area according to 1986 statistics is around 27 per thousand; this applied to a population of 4 million would result in 108,000 births annually. According to the CDC report (CDC 1991), for every 10,000 infants born to mothers whose blood lead level decrease by 1 ug/dl during pregnancy, there would be 1 fewer infant mortality.

Numerous studies have been conducted to determine the relationship between blood lead and blood pressure. These studies are most applicable in the range of blood lead levels of 5 to l5ug/dl. A recent OECD (OECD, 1993) report based on many such studies concluded that for any two- fold increase in blood lead level, there is a mean1 mm Hg increase in blood pressure. Since there is considerable uncertainty in both the exposure assessment and the dose response assessment to be applied, further relationships between increased blood pressure and other cardiovascular effects such as heart attacks and stroke were not established.

Discussion

The results of the present study represent preliminary efforts at generating a database

of information not only on human exposures but also to quantify the extent and magnitude of health damage consequent to such exposures. Clearly, the risk estimates calculated in the study are based on very little exposure information. It is not the intention of the investigators to make sweeping conclusions based on the information collected but instead identify the data gaps and consolidate available formation for further application on a health risk assessment framework.

While it may be possible to quickly refine the risk estimates with better exposure data based on established dose-response relationships, there is a need to corroborate these relationships based on fresh epidemiological studies on Indian populations or on meta- analysis of available such studies.

It would also be crucial to gather information on contributions from specific exposure pathways for a particular geographical area (as there may be considerable variations between regions) so as to determine the nature and extent of measures aimed at exposure reduction. This information will also allow a comparative health risk assessment to be made between lead and a host of other pollutants in the ambient environment.

lead levels. Use of the CDC kit costs around Rs. 250 ($6) per sample and this would preclude majority of the school children from being screened on a regular basis. Costs associated with atomic absorption spectrophotometry are less but are fraught with quality control problems associated with analytical laboratories.

It is hoped that the investigators would address many of the uncertainties clouding the assessment of health risks with a broader study. Once complete the study could serve as a model for assessment of health risks in India for lead and the myriad of other environmental problems that confront the population of developing countries.

References

1. Centers for Disease Control ( 1991 ). Strategic plan for elimination of childhood lead poisoning.
2. Pirkle, J. L. et. al. (1985) The relationship between blood lead levels and blood pressure and its cardiovascular implications. American Journal of Epidemiology. 121: 246-258.
3. Marcus , 1989. Contribution to a risk assessment for lead in drinking water. USEPA report.
4. NEERI, Air Quality Status report, 1992.
5. OECD Risk Reduction Monograph No 1. Background and experience with reducing risk 1993.
6. Schwartz J. (1988) The relationship between blood lead and blood pressure in the NHANES II Survey. Environmental Health Perspectives. 78: 15-22
7. Schwartz J. (1993) Neurotoxicology. l4: 2/3.
8. USEPA (1987) Methodology for valuing health risks of ambient lead exposure

Case Series in Vellore

Dr. A. M. Cherian

A few cases highlighting some unusual sources of clinical lead poisoning in Vellore, India are presented herewith.

Case 1: A forty-five year old lady was brought to emergency with seizures; she had a history of generalized seizures of 5 years duration and diminished vision of 2 years duration. She was previously seen in ophthalmology and neurology where a diagnosis of optic atrophy was made and was continued on anti convulsant drug. She was also given treatment by her local doctor for hypertension and episodes of abdominal pain and vomiting.

her BP was 180/100 mmHg. Fundus examination revealed optic atrophy with a visual acuity of 6/60 in both eyes. Investigation showed anemia with PCV of 28%,and 24 hrs lead level of 173 mg (Normal-45-120mg).Serum lead level was 135 ægm%. EEG showed bilateral slow wave dysfunction.

Bone marrow exam showed ring conderblast. All other investigation including CT brain and lumber puncture were normal. Diagnosis was lead poisoning and she was treated with penicillamine and improved gradually. The source of poisoning was the cooking utensil used for Rasam, which was kept in it for long periods for fortification of taste.

Family screening - Husband 50 years, staying with patient had slight tremor of bands and investigations showed lead poisoning, and he was treated with penicillamine.

Case 2: 32 years old male was admitted for severe upper abdominal pain and vomiting of 2 days duration. He gave a history of similar episodes during the last 1 year. Routine investigations including U/S, Endoscopy, Amylase, was normal, and other blood tests were normal. Further investigation proved it to be lead poisoning and he was treated with penicillamine.

He works as a laborer in a Battery factory exposed to battery fumes, and had contact with lead every day. Two other patients from the same factory were brought for check up with very non-specific complaints like headaches, and confusion. Investigation revealed mild elevation of lead.

Case 3: A 47 year old man was seen in OPD for weakness of right hand of 1 month’s duration. On examination, he had right wrist drop. Investigations revealed lead poisoning.

Source of lead: Cooking utensils + Water storage after boiling for drinking water.

Panel Discussion

The group discussed the seriousness of the nature of lead poisoning especially in big towns and cities, especially in children.

Four most common sources seen were:

1. Leaded Petrol and other vehicular fumes and factory fumes.

1. Dumping of lead compounds (through purchase for reprocessing), especially used battery.

3. Battery factories.

The following suggestions were made to combat these above problems.

1. Increase public education and awareness - through media, schools.
2. Adopt techniques which some of the other countries have done, who have already overcome the problem by adopting change over to unleaded petrol through government legislature. The economic pressure exerted by some groups or companies or countries should be made known to public so that public opinion can bring about change in government decision making.
3. Get factories that emit fumes to have regulatory measures.
4. Some occupational groups like battery workers to be made aware and factory owners to arrange regular checkup for employees.
5. Dumping waste products by other countries must be prevented, influencing through WHO, UN, World Bank, Government etc.

Pollution in Hyderabad

Dr. Mohan Ram

Introduction

Hyderabad, the capital city of Andhra Pradesh State, with a population of more than 40 lakh (4,000,000) has many large, medium and small-scale industries. The city has more than 7.5 lakh vehicles plying on the road everyday. Available information reveals disturbingly high levels of air pollutants in the environment. The pollution in Hussain Sagar lake and nearby Patencheru industrial area was highlighted already at the national level. Hence, a detailed scientific study was undertaken with the following objectives:

1. To ascertain the present perceptions of the Hyderabad city population on environmental pollutants
2. To assess the pattern of exposure of the population to environmental pollutants in

   different areas of Hyderabad city.

3. To analyze the environment-related deviations among general population and high-risk groups in Hyderabad city.

The survey was conducted in two phases in Hyderabad and surrounding 9 municipality areas covering a total of 5260 households. Water, road and industrial points were selected as source points. In the first phase, morbidity resulting from water and air pollution and perceptions of the people on diseases caused by the pollutants were studied. Five hundred and twenty adults were selected by systematic random sampling from among the study households for obtaining the perceptions of the people on the diseases caused by water and air pollution, food contamination, overcrowding and inadequate ventilation.

The second phase focussed on the levels of exposure of children up to 6 years of age to lead. For this study, roads in Hyderabad City were categorized into four groups based on the traffic load viz., high, medium, low traffic and industrial locations. Around 200 households with children up to 6 years were selected randomly from these traffic corridors. Samples of household dust, water, food as well as blood samples from children were collected and lead levels were estimated by Inductively Coupled Plasma Spectrometry (ICP) method.

Observations

1. Acute diseases were observed in 24.6% and chronic diseases in 7.6% of the population studied. ARI, skin diseases, diarrhea and malaria were identified as major acute problems. Higher incidence rates were found at industrial locations. Occurrences of both acute and chronic diseases were observed nearer to the source points. Wide variations in morbidity pattern were observed in different locations in the study area.
2. Initially, only one-third of the respondents answered correctly regarding perceptions pertaining to diseases. The correct response rate increased to around 80 per cent after probing and providing leads. The incorrect response was around IS per cent among illiterates and around 10 per cent among literates.
3. About 46 per cent of the respondents were ready to participate manually in corrective actions against environmental pollution, while 24.6 per cent were willing to contribute financially for corrective actions and upkeep of the environment.
4. The mean blood lead level among children was found to be 15.31 mg/dl. The international standard for safe limits is 10 mg/dl as proposed by CDC (Centre for Disease Control & Prevention), Atlanta, USA. Higher mean blood Lead levels were observed among children belonging to the age group 0-2 yrs. The levels were related to the traffic load. In high, medium, and low traffic areas, blood Lead levels were 17.4, 12.7, and 11.9 mg/dl, respectively.
5. A strong inverse relationship was observed between the mean hemoglobin levels and blood lead levels. In the industrial area, very low mean hemoglobin values were observed. The study brings to light increased levels of lead in blood at a very young age amongst the children of Hyderabad city.

Follow-up Action

1. Intensive environmental education is required. Raising the awareness among the common people regarding degrading environmental quality and the possible health risks can go a long way in developing healthy practices and minimizing the pollution. Educational institutions, NGO’s, local bodies, mass media, corporate bodies and trade unions can play a vital role in creating necessary awareness.
2. Traffic news bulletins broadcast from radio and TV stations daily (morning and evening) in the city, highlighting the speed of the traffic flow and suggestions for alternative road selections for various important destinations, can yield good results.
3. Emergency plans should be prepared for potentially hazardous industries.
4. Periodic screening of children up to 6 years for blood Lead levels is warranted. Facilities need to be provided for treating children showing very high blood lead levels, using chelating agents. A long-term monitoring of children with high blood Lead levels is also suggested.
5. Pedestrianisation of all main business centers should be encouraged.
6. Water analysis kits for field level functionaries and domestic users have to be provided
7. A substantial degree of intersectoral coordination is needed for environmental management.

Development of Personnel Management Information System (PMIS)

One of the objectives of the National Training Project (NTP) has been to improve the efficiency of human resource development. Personnel management is one of the key managerial functions. For discharging this responsibility efficiently, policy makers of health sector (as in any other field) need to have tools for decision making and to facilitate optimal utilization of personnel resources and manpower planning. There is thus a need for a versatile management information system in relation to health personnel.

Occupational and Lifestyles Determinants of Blood Lead Levels in Madras

Dr. Vijayalakshmi Potula

The principal changes produced during acute or chronic lead intoxication are to the hemetopoietic, central nervous, cardiovascular, and renal systems. Lead enters the circulation mainly after inhalation and ingestion. About 30-85% of inhaled lead aerosol deposits in the lungs, and 40-100% of the deposited lead is absorbed into the blood. The exact proportion depends on the particle size, with all of the smaller particles being almost completely absorbed.

Lead content in the atmosphere is higher than normal in major metropolitan cities in India. Specifically the lead concentrations have been shown to range from 0.006 to 2.19 ug/m³ in these cities and found to correlate with levels of automobile exhaust and industrial emissions.

The traffic police, bus driver and the automobile mechanic in a large metropolitan city are generally exposed to lead, and may experience more environmental stresses than by the other city dwellers. These individuals have additional risk from exposure, as lead may be found in community air as well, and cessation of work does not necessarily terminate their exposure.

Since information about the blood lead levels of various occupational groups exposed to lead-containing exhaust from automobiles in Madras was not available, this study was conducted with the following objective: to assess the relationship of blood lead levels to occupational exposure resulting from (a) the combustion products of leaded petrol and (b) several lifestyle factors (smoking, alcohol consumption, and diet) among men from four occupational groups in Madras, India.

All subjects (traffic police, bus drivers, auto-shop workers and office workers) volunteered to participate in the study. Blood lead was analyzed using Graphite Furnace Atomic Absorption Spectrophotometer (GFAAS). The study design was cross-sectional with blood lead as outcome variables, and job category, duration of employment, age, smoking, alcohol consumption and diet as explanatory variables. Univariates were calculated, and blood lead levels were then examined across categories of each variable. The significance of differences was evaluated by t-test or analysis of variance. Finally, a multivariate linear regression model was constructed, beginning with a model including all the potential predictors and proceeding by backward elimination until no variable could be dropped without a decrease in the total model r2 of 10%. Dummy variables were used to denote each occupational category, with office worker as the referent category.

The subjects ranged in age from 21-58 years, with a mean age of 42.5 years. Blood lead levels increased with age. All three occupational groups had significantly higher blood lead levels than that of office workers. Auto-shop workers had the highest levels followed by the bus drivers and traffic police. The minimal level auto-shop worker (7.2ug/dl) was higher than the minimal level for any other group. The 25^th and 75^th percentile for auto-shop workers was 2-3 times higher than those for traffic police and bus drivers.

The differences in the blood lead levels of the three exposed groups may have reflected the different levels of lead pollution in their respective areas of occupation.

Traffic police and bus drivers are benefited by wind movements that dilute their exposures. In addition, these employees are occasionally sent to work in places with low or moderate traffic levels and they work relatively short (four-hour) shift. In contrast, auto-shop employees work for eight hours at a time in confined spaces that are dusty and littered with automobile scrap. This could be the reason for higher blood lead levels in auto-shop employees.

The mean duration of employment for police, bus driver and auto-shop worker were 16.2, 12.9, and 11.8 years. Blood lead levels did not correlate with the duration of employment. The half-life of blood lead is only 18 days, with a mean life of 26 days. Hence, blood lead levels reflect only recent exposure, which may explain why blood lead did not seem to correlate with employment duration in our study.

Smokers had a higher mean blood lead than nonsmokers, but this difference was not statistically different. The median level for non-smoker was higher than that for smokers. The individual who had the highest blood lead level (40.2 mcg/dL) was a smoker. Vegetarians had significantly lower blood lead than non-vegetarians.

In the final model, job category and diet most strongly predicted blood lead levels. The relation was significant (p < 0.05). The total r2 for the model was 0.10. Duration of employment, smoking and alcohol consumption were not found to be significantly related to blood lead in this model. The magnitudes of the differences that were observed could not be reliably estimated because of the small sample sizes.

This is the first epidemiological study of occupational exposure to combustion products of leaded-petrol in Madras, with close control over possible confounding factors. The small study population and the inability to generalize the results to other groups are the study limitations.

The present study confirms the importance of occupational factors as determinants of blood lead levels in Madras, where leaded petrol is used as the primary fuel. The results should offer further incentive for a change to unleaded petrol throughout India.

A Review of Lead Poisoning Sources in India

Dr. Vijayalakshmi Potula

The goal of primary prevention of lead poisoning is to reduce lead exposure. The identification of the source of lead exposure is essential to removing lead from the environment. Informing the community, especially parents of young children, about the sources and taking preventive measures is thus important.

Lead is the earliest metals smelted by man because of its low melting point, easy casting and relative stability. Lead is mentioned in the five thousand years old Indian epic Mahabharat and is found in the excavation of its contemporary town Mohenjo-Daro. Older scriptures Cchandogya Upanishad and Yajurveda also clearly refer to lead¹.

The major man-made sources of lead include automotive industry, mining activity, base metal smelting and refining, coal-powered power stations, cement manufacture, fertilizer production and ferroalloys².

Sources of Lead Emission in India

• Folk and Herbal remedies from the Indian subcontinent is a significant unrecognized source of lead toxicity³. Ayurveda, a traditional type of Indian medicine, uses lead and mercury as active ingredients. Lead poisoning in an Indian patient following the use of Indian herbal remedies for the treatment of diabetes is also reported⁴.
• Surma use has persisted especially in the Northern Indian subcontinent, for both medical and mascara-type cosmetic traditions, and is likely to induce lead poisoning in some children. Surma is available as fine powder or heavy crystals of mineral lead sulfide containing 34-90% lead w/w. The color varies from shining deep black to dull gray brown. In some market samples, adding talc and other ingredients may reduce the lead content to 1%¹. Eye rubbing and finger licking could be the crucial factors in inducing lead poisoning in surma-using children.
• Industrial wastewater directly entering aquatic systems is another source of lead pollution in water. The impact of metal contaminated lakes on the quality of ground water by seepage is of prime concern in India⁵.
• Lead Storage batteries: The total production of the lead-acid batteries in India is about 8 million batteries per year ⁶. Nearly 10, 000 kg of lead is consumed in the production of every 1000 such batteries, and the estimated release of lead from various sources in the production of 1000 such batteries is nearly 11.35 Kg/1000 batteries. Out of these 11.35 Kg, 5.45 kg is estimated to be released as emissions and 5.90 kg as part of the wastewater or effluents⁶.
• Small-scale foundries, secondary lead smelters and lead storage batteries are sources of lead exposure in urban slum children in Bombay⁷. The major lead mining industries are located in Rajasthan and Orissa while smelting is being done in Vishakapatnam, Dhanbad, Thane and Chittorgarh. Estimated approximate production is 10, 000 million tons per day in mining units and almost 70, 000 in smelting units. Lead poisoning among Indian silver jewelry makers has been reported⁸. An unexpected mortality of more than 300 cattle near a lead reclaiming factory from lead storage batteries and soft drink cans is attributed to toxic levels of metals in the body⁹. Lead based pigment and paints and printing press are other important sources of industrial lead pollution in India.
• There are several dietary sources of lead contamination in India. Lead leaching from Indian pressure cookers while cooking especially from the rubber gasket and safety valve are two sources of lead contamination of cooked food in India¹⁰. Lead uptake from beer in India¹¹, lead contamination in various food colors¹², lead content of food samples¹³ and cereal products¹⁴ have all been investigated and reported.
• Heavy vehicular traffic in urban areas in India is the major problem. The continued use of leaded gasoline in India is the major source of high environmental lead concentration^{15, 16}. The total production of petrol is 1.5 million tons per year (MTPY). Out of this 4.8 MTPY is low leaded petrol with a maximum permissible limit of 0.15gm/litre¹⁷. The total estimated release of lead from vehicular emissions is 640 TPY. Fifty to seventy percent are released as emission and the rest as deposits on the emission system. Among the four major metropolitan cities, lead emissions are highest in Delhi, followed by Calcutta, Mumbai and lowest levels in Chennai. The increasing two wheeler population is a major source of pollution (58.7%).

Pathways of Lead Entry into the Human Physiological System

The four main routes of entry of lead into the human body are food, drink, air and dust. The respiratory uptake of lead from air depends on total lead concentration, particle size distribution, particle shape, chemical composition, physiochemical properties and respiratory volume. Factors influencing blood lead levels are cigarette smoking, alcohol consumption, drinking water, soil and dust, occupational exposure, nutritional status and urban Vs rural differences. A study on occupational and lifestyle determinants of blood lead levels in Madras, India¹⁸ is reported in detail.

References

Gogte ST, Nandita Basu, Seeta Sinclair, Ghai OP, and NK Bhide. Blood lead levels of children with Pica and Surma use. Indian J Pediatr 1991; 58:513-519.

Nriagu JO, 1978. Lead in the atmosphere. In Nriagu JO Ed., The biochemistry of lead in the environment Part A Ecological cycles Elsevevier /Nth Holland 137-184

Smitherman J and Harber P. A case of mistaken identity: herbal medicine as a cause of lead toxicity. American Journal of Industrial Medicine.1991;20(6): 795-8.

Keen RW, Deacon AC, Delves HT, Moreton JA, and Frost PG. Indian herbal remedies for diabetes as a cause of lead poisoning. Postgrad Med J. 1994;70: 113-114.

Srikanth R, Madhumohan Rao A, Shravan Kumar CH, and Anees Khanum. Lead, cadmium, nickel, and zinc contamination of ground water around Hussaine Sagar Lake, Hyderabad, India. Environ Contam. Toxicol. 1993; 50:138-143.

CPCB. Comprehensive survey of the battery industries in India. 1993. Central Pollution Control Board.

Shenoi RP, Khandekar RN, Jayakar AV, Ragunath R. Sources of lead exposure in urban slum school children. Indian Pediatrics. 1991; 28:1021-1027.

Behari JR, Singh S, Tandon SK, Wahal AK. Lead poisoning among Indian silver jewelry makers. Annals of occupational hygiene. 1983;27(1):107-9.

Dogra RK, Murthy RC, Srivastava AK, Gaur JS, Shukla LJ, Varmani BM. Archives of environmental contamination and toxicology. 1996;30(2):292-7.

Raghunath R and Nambi KS. Lead leaching from pressure cookers. Science of the total environment. 1998.;224(1-3):143-8.

Srikanth R, Ramana D, Rao V. Lead uptake from beer in India. Bulletin of environmental contamination and toxicology. 1995; 54(5): 783-6.

Khanna SK, Singh GB, Hasan MZ. Metal contamination in various food colors. Journal of the science of food and agriculture. 1976;27(2):170-4.

Lalit BY, Ramachandran TV, Rajan S. Lead-210 content of food samples in India. Radiation and Environmental Biophysics. 1980;18(1):13-17.

Srikanth R, Ramana D, Rao V. Role of rice and cereal products in dietary cadmium and lead intake among different socio-economic groups in south India. Food additives and contamination. 1995;12(5):695-701.

Aggarwal AL, Patel TS, Rayani CV, Chatterjee SK. Biologic effects of airborne lead on occupationally exposed traffic policemen and permanent shopkeepers stationed at Ahmedabad city. 1979;70:650-6.

Khandekar RN, Raghunath R and Mishra UC. Levels of lead, cadmium, zinc, and copper in the blood of an urban population. The science of the total environment. 1987; 66:185-191.

Jain CP. Personal Communication. 1998. Safety and environmental protection, Indian Oil Corporation Ltd., Scope complex, New Delhi.

Potula V and Hu H. Occupational and lifestyle determinants of blood lead levels among men in Madras, India. International Journal of Occupational and environmental health. 1996;2(1):1-4.

Two High-Impact Cases of Lead Poisoning in India

Dr. A.D. Sawant

1. Industrial Pollution in Maharashtra

An episode of cattle mortality near Talasari on the border of Maharashtra and Dadra Nagar Haveli was reported in early nineties. On observing the lead emission form Hindustan Alloy Manufacturing Company, we undertook an environmental impact assessment study of the affected region. The villages, namely, Udhwa, Kalamdevi and Kherdi with vast agriculture land around, surrounded the lead smelter of the industry. Large numbers of cattle deaths had already occurred and were still going on, presumably due to heavy intake of lead through grazing on the surrounding land. Tribal residents around were also badly affected, and symptoms of lead poisoning were clearly observed.

Analytical data of soil, sediments, water and biological samples showed high accumulation of Pb, associated with other toxic elements such as Zn, Cd, Cu, As, Sn, Cr and Sb etc. In some cases values were found much higher than permissible levels^1-5. The results of analysis and symptoms observed, indicated a clear case of lead poisoning. This study showed pollution of the factory environment, and exposed the negligent attitude of the management.

The concerned factory is situated at about 118 km from Mumbai at village Udhwa (Fig.1). The river Dongarkhadi is flowing through the area. Dust particles from the factory were spread around and deposited on vast surrounding land due to emission from smelter. Raw materials like battery waste, aluminum cans, coke blocks and Pb slurry were found stored on open land near the factory. Grey deposits in adjoining dried nullah were indications of waste material being flown away in monsoon. Absence of any other factory in the area suggested the concerned lead alloy making industry as the only source of Pb pollution in the area.

Samples and Analysis

Suitable procedures were adopted at every stage of sampling, sample pretreatment and estimation with care to avoid errors due to contamination. The concentrations of Pb and other metals in all samples were determined by Atomic Emission Spectroscopy (ICP-AES).

Sampling

Sampling sites were selected all around the factory. All the samples were collected in acid washed and steam cleaned polythene bottles. Water and sediment samples were drawn from Dongarkhadi River. Soil and grass samples, either grab or composite, were collected at the distance between 10 to 500 meters from the factory, from the grazing land, paddy fields and nullah. Having noticed thick deposits, leaves of vegetation and tree barks samples were collected. Paddy grains from fields 50 meters away from the factory, and household rice samples were collected. Biological samples such as blood, urine, cowdung and bones of dead animals, and blood and urine of humans, including those working in factory, were collected. Assistance of veterinary and medical doctors was sought for blood samplings of cattle and humans respectively.

Sample preparation

Solid samples were oven dried at 110^OC for 8 to 20 hrs. The dried samples were ground to fine powder and passed through 80 mesh sieve. Water samples were filtered and known volumes were concentrated to 100 ml in presence of nitric acid. Leaves washings were collected separately. All samples were digested by wet ashing method in analytical grade acids i.e. HNO₃, HCl and HClO₄ or their suitable mixture. Samples were diluted to 25 to 100 ml volume keeping 0.1M nitric acid strength.

Results and Discussion

The results are given in Table 1&2. From the analysis of variety of samples from the affected area, it was observed that large quantities of Pb were emitted into the environment. Other toxic metals were also associated with Pb. Since toxic metals spewed were deposited on grazing land, cattle were the first victim of Pb pollution. It was observed to be prima facie case of lead pollution and poisoning. Nearly 350 cattle head perished within few months. The cattle listed in Table-2 subsequently died in a few days. Dharma, Jayanti and Kanti were residents staying within 100 meters of factory front, and were noticed with heavy deposits on their body, clothes and on their household belongings. The cattle were showing lot of salivation, convulsion and collapse. Many instant deaths were witnessed by the analyst. On examining the residents around the factory, they were showing symptoms of loss of appetite, colic pains, boils, loss of memory, pain in joints, problems in urination and passing of stool. Many old ladies were found to be hapless because of continuous sickness and few were found to be mentally irritated. This pathetic seen was noticed by authorities when the matter was reported through these studies and the factory was ordered closed. Subsequently, it reopened after doing a lot of corrective measures in about 8 months time.

2. Blood Lead Levels in Mumbai Traffic Police

Mumbai City is densely populated and traffic density is nearly 500 vehicles per km. At present there are about 8.4 lakh vehicles on the city roads in Mumbai. Currently only about 10% vehicles use unleaded gasoline and of the remaining approximately 40% of the vehicles run on diesel. Based on very conservative estimate of a 20km average run per vehicle per day, an average vehicle consumes 2 lit/day of leaded gasoline. Considering 0.56 g Pb/lit, by very conservative estimate alone, vehicular emission of Pb comes to about 400 kg per day of lead in Mumbai City.

The traffic police persons stationed at heavy traffic junctions were monitored for blood lead levels. The blood lead values obtained are given in Table 3. The control samples were also analysed including those of the family members of constables who had an average blood lead level of 18 m g/dl.

As a precautionary measure, after these finding, Government of Maharashtra has taken some measures like frequent shifting of the duties of constables and providing them breathing mask. It has now been proposed by the Government of India to make unleaded gasoline available nation-wide by the year 2001.

Table 1: Results of Analysis (Representative)

 

 

Table 2: Results of Analysis (Representative)

 

Table 3: Blood lead levels in Mumbai Traffic Police

• K series: Blood samples collected from Churchgate, Marine Drive,
  Mahalakshmi, Haji Ali, Worli Naka, Shivaji Park, Dadar T. T. circle, Byculla, P. D’Mello Road.
• N series: Blood samples collected from Sion circle, Kurla Depot, Ghatkopar, Sakinaka.

  References

1. "Blood analysis results of suspected Pb poisoning cases referred by Bombay Hospital", R. N. Khandekar, Radha Raghunathan, B A R C report(1990).
2. E P A (1979).
3. Pb in human environment report-National Academic Sciences- Washington-D.C.(1977).
4. Environmental Health Criteria-2- Pb WHO (1977).
5. Ewing, R.A., M. A. Bill and T. A. Lutz (1979) "The health and environmental impacts assessment of the Pb for limitation office of toxic substances".

TOP