An essential potential hazard across all humans and animals on this globe, including those in our native country of Bangladesh, is indeed the environmental metal contamination caused by human activity. It has raised awareness of the danger that heavy metals as lead pose to the biosphere both right now and in the future due to their invisible effects. In developed countries, lead poisoning no longer occupies the predominant position it once did. By contrast, in developing countries, lead poisoning is still commonplace, and on a worldwide scale it remains the most common of the occupational poisonings. Lead is released into the environment primarily through air by burning of gasoline and solid wastes and breaking and manufacturing of lead acid storage batteries, the largest used category, tend to be recycled. There is a large number of occupations where exposure of lead occurs in our country like lead acid storage battery industries. Lead is also used in organic form as tetraethyl lead and tetramethyl lead in petroleum. This lead is released into environment as inorganic after its impartial combustion by motor vehicles. As a result, lead exposure is a widespread problem. Nevertheless, airborne lead emissions have drastically decreased in recent years. Lead can also be absorbed via contaminated drinking water, fish, meat, vegetables, fruit, and nails and skin (Biswas et al., 2021).

In Bangladesh, a small number of individuals engage in the lead acid storage battery industry. Most of such firms dont really adhere to factory policies and procedures, and the workers handle hazardous materials like lead and Sulphuric acids without being aware of the risks. The lead batteries are made and broken using traditional methods. In order to recover the lead and plastic within, the battery is broken. Metallic lead plates coated with lead oxide and lead sulphate are separated out from plastic casing using processes that commonly expose workers to lead fumes and dust. To decrease the battery, torches are used to cut through the outer case, creating additional lead fumes, nails and skin contamination also occurs during manufacturing process of the battery. The impact of lead on health is generally cumulative. As a result, prolonged exposure to trace amount of lead is dangerous for human body. In accordance with toxicity and data obtained from clinical investigations and various other studies such as animal experiments, very low allowable limit has been recommended by various regulatory authorities for lead in working place and environment (Nahid et al., 2019).

The purpose of the current study was to ascertain how lead exposure affected some of the impacted individuals health. In order to determine size of the issue may be determined and the appropriate actions can be taken.

Justification of This Study

There are no lead mines in Bangladesh. All lead is sourced from abroad and used after being smelted. The majority of the lead is imported in various lead compounds. In our nation, many occupations, such as those that produce lead acid storage batteries, expose workers to lead. Lead and lead compounds have been utilized by painters, composers for printing presses, workers who grind with power equipment, welders, and other employees in foundries. Tetraethyl and tetramethyl lead are organic forms of lead that are also utilized in petroleum. This lead is released in the environment as inorganic after its impartial combustion by Motor vehicles. As a result, lead is exposed to a vast population. However, due to greater usage of unleaded gasoline as well as gradual limits on the lead level of gasoline, emissions of lead into the air have substantially decreased in recent years. Lead can also enter the body via contaminated drinking water, fish, meat, vegetables, fruit, and nails and skin. In Bangladesh there are some people working ion Lead acid storage battery factories and most of these facilities do not follow the factory acts and rules and use conventional method to manufacture as well as break-ing the lead battery. Exposure to lead fumes and dust routinely occur doing manufacturing. Nails and skin contamination also occurs. In abroad some studies were done on lead acid storage battery workers but there was no such study yet done in Bangladesh. The studys findings will aid in determining the scope of the issue, and they may also offer recommendations for improving the working environment and raising awareness of the negative effects of lead exposure within the study group (Alam and Bahauddin, 2015).

Research Question

Major health problems amongst lead acid storage battery workers.

Objectives

A. General Objective

To identify the health problems amongst lead acid storage battery workers.

B. Specific Objective

1) To identify the morbidities amongst lead acid storage Battery workers.

2) To identify the morbidities in relation to the duration of working hours and length of job duration.

3) To find out the number of workers using personal protective device and maintaining personal hygiene.

4) To determine the socio demographic characteris-tics of lead acid storage battery workers.

Variable

 In the study following variables were considered.

Dependent Variable

Sign and symptoms attributable to lead poisoning

1) Haemopoietic system:    Anemia

2) Nervous system:Muscle and joint pain Progressive weakness Full drop wrist drop Tremor.

3) G. I. system:Loss of appetite. Blue line along the gum abdominal pain Vomiting Diarrhea Constipation

4) Cardiovascular system:Hypertension

Independent Variable

1) Age

2) Sex

3) Marital Status

4) Duration of exposure

5) Working hours.

6) Educational qualification.

7) Income

8) Exposure in previous occultation

9) Safety measures.

10) Personal hygiene

11) Medical facilities.

12) Other facilities.

Operational Definition

Progressive weakness: Complain of weakness which is increasing day by day after joining the job.

Lead colic/ Abdominal pain: Occurrence of cramping pain in the abdomen which is localized around of bellow the umbilicus after joining the job.

Lead Line: Blue or grey pigmented line may be present on the dental margin of the gums which is associated with poor dental hygiene with lead exposure.

Lead acid storage battery workers: The Workers who are primarily concerned with manufacturing process and breaking of lead acid storage battery.

Wrists drop/Foot drop: Asked and examined the patient it there was any loss of sensation, weakness or paralysis of hand or food.

Neurological or psychological problem: Asked the patient about complain of lethargy, slowness of perfor-mance, excessive sleep, confusion, mania and change of personality after joining the job.

Personal hygiene:  Total six questions were asked to the participants to assess the personal hygiene. Each answer to the question carried 1 point for “no” and 2 points for “yes” then summations of pints were done, and the status of personal hygiene was classified as -Poor hygiene: ≤8; Moderate hygiene: 9.10; and Good hygiene: 11.12.

Study Design

It was a crosssectional study.

Study Area

The study was carried out in 11 lead acid storage factories in Dhanmondi, Mohammedpur and Waizghat of Dhaka city.

Study Period

The study was conducted over a period of 12 weeks extending from 1st January to 30th March 2017. For convenience of work a schedule of activity (workflow chart) was prepared at the beginning of the study and assignments were accomplished as per schedule.

Study Population

The study population included the workers who are primarily concerned with manufacturing process and breaking of lead acid storage battery.

Sampling Technique

Purposive sampling technique has been followed in this study. A total 100 samples were collected.

Sample Size

Before starting my data collection 1 estimated that I could collect data from 8-10 respondents per day.  I collected data from the respondents for 10 days. In this way the sample size became 100.

Data Collection Tools

Inclusion of all key variables as per general and specific objective   of the study, a questionnaire was developed and pretested and required alternation and modified were made. A check list was also made to collect the physical findings regarding anaemia. Tremor and blood pressure.

Data Collection Method

Data collection was done by the researcher himself. Before interviewing, the purpose of the study was explained to the respondent and verbal consent taken from the respondent. Questionnaire part was filled in through direct interview and physical examination was done including measurement of blood pressure. 

Table 1: Distribution of the respondents by Age and Sex (Mean of Age= 23.80 years and SD= 6.35 years).

Out of 100 respondents it was found that in age group of ≤20 years. Number of respondents were 33 (33.0%), in the age group 21- 30 years. Respondents were 54 (54%) and in the age group >30 years respondents were only 13 (13%). These findings show that highest percentage lie in the age group of 21- 30 years which is the main working population in the lead acid storage battery factories. The mean age of the study population was 23.80 years with SD 6.35. The minimum age was 14 years and the maximum age was 50 years. Out of 100 respondents there was no female worker.

Table 2: Distribution of respondents by religion and marital status.

The total population 100 shows that 86 (86%) were Muslims and 14 (14%) were Hindu. On the basis of marital status, the study population was classifying into married and unmarried among which majority were unmarried 62 (62%) and 38 (38%) were married.

Table 3: Distribution of the respondent by educational status & monthly income (Mean= 2574.16 Tk SD=1252.66).

Mean= 6.06 years with SD 6.08; Min duration 3 Months and max duration 28 years. Fig. 1 Shows that out of 100 respondents 68 (68%) had work experience in lead acid storage battery factory equals or less than 5 years and 32 (32%) had work experience more than 5 years. Fig. 2 shows that 29 (29%) respondents had equal or less than 10 hours of working duration and 71 (71%) had more than 10 hours of working duration. The mean working duration was 11.05 hours with SD 1.66.

Out of 100 respondents 74 (74%) had progressive weakness with mean duration of 13.14 months and SD 15.49, 46 (46%) had a loss of appetite with mean duration of 12.36 months and SD 16.03, 53 (53%) had constipation with mean duration of 10.23 months and SD 13.20, 28 (28%) had abdominal pain with mean duration of 14.50 months and SD 23.21, 26 (26%) had muscle and joint pain with mean duration of 14.44 months and SD 15.06, 57 (57%) had anaemia and 13 (13%) tremor with mean duration of 37.15 months and SD 46.33. 

Fig. 1: Distribution of the respondent according to their duration of job in lead acid storage battery factory.

The minimum duration was 1 months for all symptoms except tremor which was 3 months and maximum duration was 96 months for progressive weakness and abdominal pain, 60 months for constipation, muscle and joint pain and loss of appetite 180 months for tremor. The above findings indicate most of the respondents complained of progressive weakness and the lowest no of respondents complained of tremor. The bar chart (Fig. 5) was drawn from Table 5 showing the frequency of positive signs and symptoms.

Fig. 2: Distribution of the respondents according to their working hours.

Out of respondents 96 (96%) had diastolic pressure less than 90mm of Hg and 4 (4%) had more than 90mm of Hg. In case of systolic pressure 73 (73%) had less than 130mm of Hg and 27 (27%) had more than 130mm of Hg. The above result shows that 4 respondents had hypertension whose diastolic pressure had more than 90 mm of Hg.

Table 4: Distribution of respondents by their previous work experience.

Out of 100 respondents the age group below 20 years, 14 (42.42%) had progressive weakness, 9 (27.2%) had loss of appetite, 7 (21.2%) had constipation, 3 (9.09%) had abdominal pain, 2 (6.0%) had muscle and joint pain, 7 (21.2%) had anaemia and 1 (3.03%) had tre-mor. Age group between 21-30 years 48 (88.88%) had progressive weakness, 28 (51.85%) had loss of appe-tite, 39 (72.22%) had constipation, 19 (35.18%) had abdominal pain, 15 (27.77%) had muscle joint pain, 40 (74.07%) had anaemia and 9 (69.23%) had tremor. Age group of above 30 years 12 (92.30%) had pro-gressive weakness, 9 (69.23%) had loss of appetite, 7 (53.85%) had constipation, 6 46.15%) had abdominal pain, 9 (69.23%) had muscle and joint pain, 10 (76.93%) had anaemia and 3 (23.07%) had tremor. The table indicates the maximum frequency of clinical signs and symptoms were in the age grouped between 21-30 years. The statistical result shows significant associa-tion between age and clinical signs and symptoms except for tremor.

Fig. 3: Distribution of the respondents according to the result of Personal Hygiene.

The respondents who worked in Lead acid storage battery factory less than 5 years. Among them 44 (64.70%) had progressive weakness. 29 (42.64 %) had loss of appetite, 29(42.64%) had constipation, 12(17.65%) had abdominal pain, 6(8.82%) had muscle and joint pain, 31(45.58%) had anaemia and 2 (3.0%) had tremor. The respondents who worked more than 5 years 30 (93.75%) had progressive weakness, 17 (53.12%) had loss of appetite, 24 (75.0%) had constipation, 16 (50.0%) had abdominal pain, 20 (62.50%) had muscle and joint pain 26 (81.25%) had anaemia and 11 (34. 38%) had tremor. The result suggests that more duration of job, the more prevalence of clinical signs and symptoms except for loss of appetite and this association was also statistically significant. 

Fig. 4: Distribution of respondents by using Personal Protective Equipment (PPE).

X2 = 1.47, P= 0.000 Table 9 shows that the respondents who had less than 5 years job experience, among them 34 (62.00%) had less than 3 symptoms, 18(33.3%) had 4-58 symptoms, 2 (3.70%) had more than 5 symptoms and the respondents who had more than 5 years. Job experience 7 (22.5%) had less that 3 symptoms, 12(38.70%) had 4-5 symptoms and 12 (38.70%) had more than 5 symptoms. There is a positive association between length of job duration and frequency of symptoms which was also statistically significant. 

Table 5: Distribution of the respondents according to their sign and symptoms.

The respondents whose work duration were less than 10 hours among them 20 (68.96%) had progressive weakness, 8 (27.58%) had loss of appetite, 11 (37.93%) had constipation, 8 (27.58%) had abdominal pain, 6(20.68%) had muscle and joint pain, 14 (48.27%) had anaemia and 4 (13.79%) had tremor and the respondents whose work duration were more than 10 hours among them 54 (76.05%) had progressive weak-ness, 38(53.52%) had loss of appetite, 2(59.15%) had constipation, 20(28.16%) had abdominal pain 20 (28.16%) had muscle and joint pain , 43(60.56%) had  anaemia and 9(12.67%) had tremor. 

Fig. 5: Distribution of respondents by Clinical signs and symptoms.

The respondents who previously worked in lead acid storage battery factory, among them 8(88.8%) had progressive weakness, 6(66.6%) loss of appetite, 5(55.5%) had constipation, 5(55.5%) had abdominal pain, 6(6. 66%) had muscle and joint pain, 8(88.8%) had anaemia and 2(.22%) had tremor. The respondents who were previously motor garage workers, among them 5(83.33%) had progressive weakness, 4(66.6%) loss of appetite, 5(83.3%) had constipation, 4(66.6%) had abdominal pain, 3(50.0%) had muscle and joint pain, 5(83.3%) had anaemia and 1 (16.66%) had tremor.  The results fail to show statistically significant association between previous work experience and clinical signs and symptoms.

Table 6: Distribution of the respondents by systolic and diastolic BP.

8 respondents were illiterate among which 7(87.50%) had progressive weakness, 6(75.0%) had loss of appetite, 6(75.0%) had constipation, 1 had (12.50%) abdominal pain, 1 (12.50%) had muscle and joint pain, 4(50.0%) had anaemia and tremor was absent. The respondents who were in the group of class 1-5 among them 32(64.0%) had progressive weakness, 17(34.0%) had loss of appetite, 21(42.0%) had constipation, 7 had (14.05) abdominal pain, 9(18.0%) had muscle and joint pain, 22(44.0%) had anaemia and 4(8.0%) had tremor. Among the respondents who were in the group of class 6-10 among which 35(83.0%) had progressive weak-ness, 23(54.0%) had loss of appetite, 26(61.90%) had constipation, 20(47.61%) had abdominal pain, 16(38. 09%) had muscle and joint pain, 31(73.80%) had anaemia and 9(21.42%) had tremor. 

Table 7: Distribution of respondents by Age and clinical signs and symptoms.

The educational status of the respondents shows that only 8 (8%) were illiterate and majority of the respondents 50 (50%) were in the group of class and 42 (42%) were in the group of class 6 - 10. The monthly income of the respondents of the study indicates that 38 (38%) had monthly income less than 2000tk 31(31%) had monthly income of 2001- 3000 Tk, 15 (15%) had 3001- 4000 Tk and 16 (16%) workers had income over 4000 Tk.

Table 8: Distribution of the respondents by Job duration and clinical signs and symptoms.

Table 9: Distribution of respondents by number of clinical symptoms and job duration.

The respondents whose work duration were less than 10 hours among them 20 (68.96%) had progressive weakness, 8 (27.58%) had loss of appetite, 11 (37.93%) had constipation, 8 (27.58%) had abdominal pain, 6(20.68%) had muscle and joint pain, 14 (48.27%) had anaemia and 4 (13.79%) had tremor and the respon-dents whose work duration were more than 10 hours among them 54 (76.05%) had progressive weak-ness, 38(53.52%) had loss of appetite, 2(59.15%) had cons-tipation, 20(28.16%) had abdominal pain 20 (28.16%) had muscle and joint pain , 43(60.56%) had  anaemia and 9(12.67%) had tremor. The Table 10 shows that the respondents whose work duration more than 10 hours had more positive clinical signs and symptoms but the result fails to demonstrate any  statistically significant association between working hours and clinical signs and symptoms.

Table 10: Distribution of the respondents by working hours and clinical signs and symptoms.

The Table 10 shows that the respondents whose work duration more than 10 hours had more positive clinical signs and symptoms but the result fails to demonstrate any  statistically significant association between working hours and clinical signs and symptoms.

Table 11: Distribution of the respondents by previous work experience and clinical signs and symptoms.

Table 12: Distribution of the respondents according to their level of education and clinical signs and symptoms.

The Table 12 shows Out of 100 respondents 15 used PPE among them 12 (80.0%) had progressive weakness 10(66.66%) had loss of appetite, 9(60.0%) had constipation, 5 (33.34%) had abdominal pain, 7(46. 66%) had muscle and joint pain 10 (66.66%) anaemia 5 (33.33%) had tremor 85 respondents did not use PPE. In 62(72.35%) had progressive weakness 36 (42.35%) had loss of app (51.76%) had constipation, 

22(27.05%) had abdominal pain, 19(22.35%) muscle and joint pain 47 (55.29%) had anaemia and 8 (9.41%) 

had tremor was no significant statistical association between clinical symptoms and PPE.

Table 13: Distribution of the respondents by using PPE and clinical signs and symptoms.

The Table 12 shows that the prevalence of clinical signs and symptoms were more among class group of 6-10 than that of other but the result failed to demonstrate the significant statistical association based education level and clinical signs and symptoms.

Table 14: Distribution of the respondents by personal hygiene status and clinical signs and symptoms.

Table 14 shows that the prevalence of clinical signs and symptoms had more in the respondents who were amongst the group of moderate hygiene but there was no significant statistical association obtained between clinical symptoms with the status of personal hygiene.

There were total 100 respondents included in this study who worked in lead acid storage battery factory. The respondents were selected purposively from 11 lead acid storage battery factories in Dhaka city. The study revealed that during manufacturing process the workers handle the lead plate, lead oxide with naked hands so frequent lead contamination occurs which ultima-tely ingested with food. Table 1 revealed all respondents were male ages ranging from 14-50 years and majority was in the age group of 21-30 years. It is noted that there were 18 respondents among the age group of 14-18 yrs. Who are the vulnerable group prone to lead poisoning? Table 5 shows the prevalence of positive signs and symptoms attribute to lead poisoning which included Progressive weakness (74.0%) with mean duration of 13.14 months, loss of appetite (46.0%) with mean duration of 12.36 months, constitution (53.0%) with mean duration of 10.23 months, abdominal pain (28.0%) with mean duration of 14.50 months, muscle and joint pain (26.0%) with mean duration of 14.44 months, tremor (13.0%) with mean duration of 37.15 months and anaemia (57.0%). Two of the studies were conducted in secondary lead smellers who smelted lead from used automobile stor-age batteries. The first of these smelters was located in Memphis, Tennessee and employed 84 workers. The second smelter, in Salt Lake City, Utah and employed only 30 workers. Critical manifestations of lead poisoning were evident in both plants. The dominant findings were colic, gastrointestinal symptoms, anorexia, fatigue, myalgia, joint pain and extensor muscle weakness which are like my study findings. Table 6 shows that 4 respondents were found hypertensive whose diastolic blood pressure was above 90 mm Hg. Recently hypertension is defined as diastolic pressure 90 mm of Hg or above. A study was conducted to determine the lead level in blood in a lead acid storage battery in Sudan. Total 70 workers had weakness, constipation and muscle and joint pain; 6(8.57%) workers were found hypertensive (Gottesfeld & Pokhrel, 2011). 

Table 8 and 9 shows that 68 respondents worked in lead acid storage battery less than 5 years and 32 res-pondents worked more than 5 years. There was a posi-tive relationship between length of job duration and clinical signs and symptoms. The more duration means more exposure to lead hence there were more pre-valence of clinical signs and symptoms found, and this was also statistically significant except for loss of appetite. But the Table 10 revealed no association bet-ween working hours and clinical symptoms. 

Table 7 shows there were a positive relationship bet-ween age and clinical signs and symptoms and this association was also statistically significant except for tremor. Table 4 and Table 11 show the previous work experience where 9 workers worked in motor garage workshop. Lead exposure also occurs in motor garage workshop. The other previous work experience of the respondents was not significant in relation to lead exposure. So total 15 respondents had previous lead exposure and it was found that the prevalence of clinical signs and symptoms were more in these groups. Fig. 4 and Table 4 shows the status of per-sonal hygiene where maximum respondents (84. 0%) had good hygiene, (13.0%) had moderate hygiene and only (3.0%) had poor personal hygiene status. No relationship was found between status of personal hygiene and clinical symptoms. Table 11 shows that clinical symptoms were more prevalent in the group of class 6-10 but no significant association was obtained between educational status and clinical symptoms. Fig. 5 shows the safety measures taken by the respondents. Out of 100 respondents only 15 used hand gloves and 85 respondents did not use any PPE so during manufacturing process frequent lead contamination occurs which ultimately ingested with food. 

To de-case the battery, torches are used to cut through the outer case, creating additional lead fumes which are inhaled. There were no provisions for medical or other facilities for the workers hence it was not shown in the table (Majumder et al., 2021; Ahmad et al., 2019).

This research has discovered that employees are commonly contaminated to lead during the production of lead acid storage batteries. Out of 100 respondents 85(85.0%) had positive clinical signs and symptoms attributable to lead exposure. The dominant findings were progressive weakness, loss of appetite, constipation, abdominal pain, muscle and joint pain, anaemia and tremor. 4 respondents were found hypertensive. There were positive associations between clinical signs, symptoms with the length of job duration and Age of the respondents though there was no relationship found between clinical symptoms with working hours. The research was unable to determine a correlation across clinical symptoms and past employment history, educational attainment, degree of personal hygiene, or safety precautions taken. There was no provision for medical or other facilities. The personal hygiene status was good, 84(84.0%) respondents had good personal hygiene. The safety measures taken by the respondents was very poor, only 15(15.0%) used hand gloves. The studys findings could be contested for a variety of reasons, including the lack of a control group, the studys tiny sample size, the no specificity of the favorable clinical manifestation, and the absence of assessment of the participants blood lead levels. Besides all above lacking it was an attempt to find out the health problems amongst lead acid storage battery workers in Bangladesh. The study result will help to magnitude of the problem and may provide necessary guidelines for improvement of working environment and to make awareness in the study population about the health hazard of lead exposure and be useful for formulating recommendation in preventing lead exposure in battery workers and this surely will also inspire us for further research (Khan and Saadat, 2019).

I would like to express my sincere gratitude to the Executive Director of the Institute of Sustainable Innovation for Communities (ISIC), Khalid Md. Bahauddin and Abdul Kadir Ibne Kamal, Associate Professor of the Dept. of Environmental Sciences, Jahangirnagar University for guiding, mentoring, and continuous support to this excellent project.

The authors state that they dont appear to have any friction of part related to the study.