Activated Carbon Fabric Mask Reduces Lead Absorption and Improves the Heme Biosynthesis and Hematological Parameters of Battery Manufacturing Workers

Abstract

Activated carbon fabrics (ACF) mask prevents the absorption of lead and reduce its adverse effects of human health. Aim of this study to know the blood lead level and its effects on heme biosynthesis and hematological parameters after using 2 months activated carbon fabric mask of battery manufacturing workers (BMW). Blood lead level, heme biosynthesis and hematological parameters were measured by using standard method. Blood lead level (P < 0.001, − 13.5%) was significantly decreased, activated δ-aminolevulinic acid dehydratase (P < 0.001, 11.97%) and non-activated δ- aminolevulinic acid dehydratase (P < 0.001, 23.17%) enzyme activity were significantly increased, however, the ratio of activated to Non-activated δ- ALAD (P < 0.001, − 10.13%) was significantly decreased, urinary excretion of δ- aminolevulinic acid (P < 0.001, − 10.49%) and porphobilinogen (P < 0.001, − 7.38%) were significantly decreased after using 2 months ACF mask as compared to before using mask of BMW. Hematological parameters i.e Hb (P < 0.05, 13.42%), PCV (P < 0.05, 7.23%), MCV (P < 0.05, 1.9%) were significantly increased and total WBC count (P < 0.05, − 5.18%) was significantly decreased after using 2 months ACF mask as compared to before using mask of BMW. Two months using ACF mask reduces the blood lead level and improves the δ-ALDH activity and hematological parameters, decreases the urinary excretion of δ-ALA, PBG of battery manufacturing workers. Therefore, the regular using of ACF mask is beneficial to prevent the lead absorption and its adverse effects on human health.

Introduction

Lead is toxic heavy metal and a major environmental pollutant. Due to its excellent properties lead is used mainly in printing press, acid battery manufacturing, silver jewellery making, cable sheathing, soldering cans, folk remedies, color pigments, petrol additives, ceramic glazes, soldering water distribution pipes and paper industries etc. During smelting, mining, processing, use, recycling or disposal lead enters in environment [1, 2].

Lead is absorbed by the gastrointestinal tract from contaminated food, beverages, atmospheric lead inhalation and skin and deposited in soft tissues (half-life 28–36 days) and then to bones (half-life 27 years). Mainly lead is excreted through the urine (> 90%) and small amounts are eliminated via the feces, sweat, hair and nails [1, 2].

In small unorganized battery industry, majority of work is done by manually and lots of lead particles, dust, smoke and fumes are generated. All the workers in these industries are not using apron, goggles, mask and exposed to lead through inhalation, ingestion and dermal contact, which increases the blood lead levels of the workers [3] and the variety of health issues such as hematological [4, 5], kidney and liver failure [6–8], cardiovascular diseases [9], reproductive [10], immunological [11], neuropsychological [12], dental caries [13], matrix–gamma-carboxy glutamic acid protein polymorphism [14], oxidative stress [15, 16], pteridine metabolism with neurotransmitters synthesis [17], genotoxicity [18], monoamine metabolites [19] have been reported in the battery manufacturing workers after the chronic exposure to lead.

Activated carbon fabric (ACF) is known for its adsorbent characteristics, the effectiveness of these masks in bringing down the blood lead levels of battery workers was attempted [20]. Heavy metals from both industrial and drinking water has been removed by the adsorption techniques and this is good option to at least remove the heavy metals and decrease human’s chances of suffering. Definitely activated carbon stands in the fore front of the full line of adsorbents [21]. Tests conducted at the department of Chemical Engineering, Indian Institute of Science, Bangalore, India found that the 40% lead metal ions are adsorbed by activated carbon fabric. The Microbiology division of the Bombay Textile Research Association, Mumbai, India, has shown that ACF has good antibacterial activity [20].

Therefore, we have tempted to provide the activated carbon fabric mask to unorganized battery manufacturing workers and to see their blood lead level and its effects on heme biosynthesis and hematological parameters after using 2 months activated carbon fabric mask.

Materials and Methods

For this study 37 male battery manufacturing workers from Western Maharashtra, India, were recruited. Age range of study group subjects was 20–60 years. All the battery manufacturing workers were non-alcoholic; non-smoker and history of prolonged exposure to lead were part of the study group. Those battery manufacturing workers taking treatment for any major/minor illnesses were excluded from the study. The dietary intake, food habits, demographic, occupational and clinical data were collected using questionnaire and interview. Written informed consent was taken from the study group subjects in local language. They were informed about the study objectives along with health hazards of lead exposure and its toxicity. Institutional ethics committee and protocol committee approval were taken prior to recruitment and all procedures were conducted in accordance with the Helsinki declaration of 1964 [22]. Before providing activated carbon fabric mask to battery manufacturing workers the ten ml blood drawn by puncturing the antecubital vein. Each tube five ml blood was transferred in heparin and EDTA containing tube for estimation of blood lead level, heme biosynthesis related and hematological parameters.

All these parameters were measured by using the standard methods. The testing of all parameters done at Krishna Institute of Medical Sciences ‘Deemed to be’ University, Karad, Maharashtra. The blood lead level was measured by using blood lead analyzer (Lead Care II, Magellan Diagnostics Company, USA). This blood lead analyzer is based on an electrochemical technique called Anodic Stripping Voltammetry (ASV) to determine the amount of lead in a blood sample. The blood was mixed with lead care treatment reagent (0.34 M—dilute hydrochloric acid solution in water), which lyses the red blood cells and release the lead. A negative potential was applied to the sensor to accumulate lead atoms on the test electrode. The potential is rapidly reversed releasing the lead ions. The current produced was directly proportional to the amount of lead in the sample [23].

The Erythrocyte–δ-Aminolevulinic Acid Dehydratase (δ-ALAD) was estimated by the method described by Julian Chisolan et al. [24]. Erythrocyte δ-ALAD acts on δ-aminolevulinic acid (ALA) to form porphobilinogen, which reacted with modified Ehrlich’s reagent to form pink colour compound which was measured on spectrophotometer at 555 nm. Hg-TCA solution was used to stop the reaction by precipitating the proteins.

δ-ALAD activity was estimated by using this formula:

$$\mathrm{\delta }\text{-ALAD}\text{activity}\left(\mathrm{\mu }\text{mol}\text{ALA}\text{utilized}/\text{min}/\text{L}\text{of}\text{erythrocytes}\right)=\frac{\text{Net}\text{absorbance}\times 100\times 2\times 35}{\left(\%\text{Hematocrit}\times 60\times 0.062\right)}$$

where 2 = Conversion factor for ALA to PBG; 35 = Dilution factor; 60 = Incubation time (min); 0.062 = Micromolar absorptivity of modified Ehrlich’s reagent and PBG chromogen.

Erythrocyte δ-ALAD is activated by zinc acetate and ratio of activated/non-activated δ-ALAD was determined. The δ-aminolevulinic acid (ALA) was estimated in urine samples by a method described by Osamu et al. [25]. δ-ALA reacts with acetyl acetone at 100⁰c at pH 4.6 and forms pyrrole, which reacts with Ehrlich reagent to form red colour. This red colour complex was extracted with chloroform, leaving other Ehrlich positive substances in the water phase, which was measured spectrophotometrically at 555 nm. The results were expressed as microgram/L.

The porphobilonogen (PBG) in urine was estimated by method described by Mauzerall and Granick [26]. PBG in urine reacts with P-dimethyl aminobenzaldehyde in acid solution to form a red compound which was measured at 555 nm exactly after five minutes and the values were calculated according to Rimington formula (1958) [27]

$$\text{Urinary}\text{PBG}\left(\mathrm{\mu }\text{g}/\text{L}\right)=\frac{\text{O}.\text{D}\times \text{Number}\text{of}\text{Times}\text{Urine}\text{Diluted}}{70.85}$$

All the hematological parameters were measured by using fully automated Hematology analyzer Sysmax K-4500 [28].

Activated carbon fabric mask was provided to all the battery manufacturing workers and requested to use this mask 2 months regularly. We have monitored all these workers weekly by telephone and ensured about regular use of activated carbon fabric mask. The activated carbon fabric mask was Breath-O-Full Face Mask (ISO 9001-2008 and 14001:2004 certified) manufactured by Environment Care Products, Pvt. Ltd; Greater Noida. It is a respiratory mask with activated carbon fabric device, which acts as barrier against chemical and biological impurities. This mask contains a superior quality of activated carbon fabric, which is excellent absorbent of environmental toxin, pollen, atmospheric pollutant, and harmful gases. It can used in chemical industries, agrochemical industries, oil and gas industries, leather industries, pharmaceutical industries. It is easy to carry, washable, reusable, and replaceable filter, antitoxic filter made up of activated carbon fabric, comfortable breathing, adjustable nose clip, quality approved according to environmental standard. Activated Carbon Fabric (ACF) is a fibrous adsorbent, which has been obtained from an appropriate fibrous precursor by an adequate carbonization and activation process. ACF has high mechanical durability, since it is manufactured from various combinations of precursors such as regenerated cellulose (viscose rayon), phenolic resin (kynol), polyacrylonitrile (PAN) and coal tar/petroleum pitch-based fibers. ACF can be used in the form of cloth. Filament yarn cloth is treated with 5% phosphoric acid at 88 °C for about 30 min and dried at 100 °C. This material is subjected to controlled carbonization in an inert gas atmosphere for about 4 h. The resulting ACF is cooled to room temperature and activated for specific applications. Activated carbon fabric is highly porous in nature. ACF is made up of filament yarn, due to which ACF is electrically conductive and hence it can be regenerated by passing a low voltage current across the ACF surface, or by heating of ACF at 100 °C for 15 to 30 min. The distribution of pore size is in the narrow range of < 10 nm. Molecules of pollutants bouncing across the activated carbon fabric surface gradually lose their energy and finally come to rest on it. Due to weak bonds in the physical adsorption, molecules can be removed from the activated carbon fabric surface by providing heat energy [29, 30]. ACF can be easily recharge by opening the valves and filter should be removed and dipped in boiling water for 5–10 min and dry under the sun. Shelf life of this mask is approximately 6 months to one year. This work was started in the month of October 2018. Temperature and humidity in this season was low. The workers were using these masks continuously during their working hours.

Statistical Analysis

Statistical comparison between blood lead, hematological and heme biosynthesis parameters of battery manufacturing workers done after using activated carbon fabric mask, by Student’s unpaired t test usingInstat Graph Pad software for Windows Operating System and the significance was set to,* P < 0.05, **P < 0.01, ***P < 0.001.

Results

The PbB level (P < 0.001, − 13.5%) was significantly decreased, activated δ-ALDH (P < 0.001, 11.97%) and non-activated δ- ALDH (P < 0.001, 23.17%) enzyme activity were significantly increased, however, the ratio of activated to Non-activated δ- ALAD (P < 0.001, − 10.13%) was significantly decreased. Urinary excretion of δ- ALA (P < 0.001, − 10.49%) and PBG (P < 0.001, − 7.38%) were significantly decreased after using 2 months ACF mask as compared to before using mask of battery manufacturing (Table 1 and Fig. 1).

Table 1.

Before and after using 2 months activated carbon fabric mask blood leadand heme biosynthesis related parameters of battery manufacturing workers

Sr. no.	Biochemical parameters	Before using mask (N = 37)	After using mask (N = 37)
1.	PbB (μg/dl)	71.33 ± 18.29 (43–103)	67.40 ± 17.89*** (38–95)
2. Erythrocyte δ-ALAD (μmolδ-ALA utilised)/(Min/L of erythrocytes)
A.	Activated δ-ALAD	26.14 ± 5.21 (17.5–39.7)	29.27 ± 5.3*** (19.7–41.6)
B.	Non-activated δ-ALAD	16.79 ± 3.58 (10.5–24.0)	20.68 ± 3.75*** (15–27.7)
C.	Act/N-Act Ratio	1.58 ± 0.22 (1.19–2.07)	1.42 ± 0.17*** (1.08–1.78)
3.	U-δ-ALA (mg/L)	14.01 ± 3.92 (8.7–28.7)	12.54 ± 3.16*** (7.6–22.1)
4.	U-PBG (mg/L)	22.49 ± 5.85 (12.4–37.4)	20.83 ± 5.50*** (11.7–35.7)

Figures indicate Mean ± SD values and those in parenthesis are range of values

***P < 0.001, **P < 0.01, *P < 0.05, •Non-significant as compared to before using masks

Fig. 1.

Percentage change of blood lead level and heme biosynthesis related parameters after 2 months using activated carbon fabric mask with respect to before using mask of battery manufacturing workers. Acti- δ-ALAD Activated δ- Aminolevulinic Acid Dehydratase; NA- δ-ALAD Non activated δ-Aminolevulinic Acid Dehydratase; Act/NA Ratio ratio of Activated δ- Aminolevulinic Acid Dehydratase to Non activated δ-Aminolevulinic Acid Dehydratase; U-δ-ALA Urinary δ- aminolevulinic acid, U-PBG Urinary Porphobilinogen

Hematological parameters such as hemoglobin (P < 0.05, 13.42%), pack cell volume (P < 0.05, 7.23%), Mean Corpuscular Volume (P < 0.05, 1.9%) were significantly increased and total WBC count (P < 0.05, − 5.18%) was significantly decreased after using 2 months activated carbon fabric mask as compared to before using mask of battery manufacturing workers.

Discussion

After using 2 months activated carbon fabric mask there was significant decrease in blood lead level (P < 0.001, − 13.5%) has been observed as compared to before using mask (Table 1 and Fig. 1). Battery manufacturing workers are highly exposed to lead, since more lead fumes are generated during manufacturing the lead plate. For this study battery manufacturing workers from unorganized sector were included and these workers were not using proper precautionary measures like apron, goggles and mask. Lead enter into the body by inhalation, through the skin, by ingestion possibly if food consumed in the same area The fastest means of absorption of lead into the body is through inhalation. In this study significant decreased in blood lead levels after using 2 months activated carbon fabric mask, which may be due to the ACF masks prevents the absorption of lead. However, the percentage wise reduction of blood lead levels after using ACF mask was not more. It may be due mobilization of lead from soft tissues and bones to blood, since battery manufacturing workers having very high blood lead level (Mean 71.33 ± 18.29 µg/dl and range 43- 103 µg/dl) for longer period.

Activated Carbon Fabric is a new generation material with more potential and has novel applications. It adsorbs gaseous pollutants to a large extent makes suitable for personal protection masks, particularly in areas where various gases, fumes, smoke, vapors and odors are present. ACF mask can easily adsorbs chromium, copper, nickel, cadmium, cobalt, lead, zinc, iron, manganese, acids, alkalis, and anions such as chlorides, fluorides shown by Hindustan Electro Graphites Ltd. [30].

Therefore, regular using of ACF mask is beneficial to the lead exposed population to prevent the health hazards of lead.

Significant increase in activated δ-aminolevulinic acid dehydratase (P < 0.001, 11.97%) and non-activated δ- aminolevulinic acid dehydratase enzyme (P < 0.001, 23.17%) activity were observed after using 2 months ACF mask as compared to before using mask. However, the ratio of activated δ- ALAD to Non-activated δ- ALAD (P < 0.001, − 10.13%) was significantly decreased using 2 months ACF mask as compared to before using mask (Table 1 and Fig. 1).

Lead inhibits heme biosynthesis enzymes i.e. δ-aminolevulinic acid dehydratase and ferrochelatase by binding to sulfahydryl group at the active site of these enzymes. Erythrocyte δ- aminolevulinic acid dehydratase enzyme is very sensitive to lead, even at 15 µg/dl of blood lead level inhibits the erythrocytes δ-ALAD activity [1, 2]. Increase blood lead level in this study inhibits the δ-ALAD activity, however, after using 2 months masks there is significant change were observed in activated, non-activated and ratio of activated/non-activated delta aminolevulinic acid dehydratase activity.

Urinary excretion of δ- aminolevulinic acid (P < 0.001, − 10.49%) and porphobilinogen (P < 0.001, − 7.38%) were significantly decreased after using 2 months ACF masks as compared to before using masks. In battery manufacturing workers significant increased urinary excretion of δ- aminolevulinic acid and porphobilinogen were reported in previous study [15]. However, in this study slight reduction in urinary excretion of δ- aminolevulinic acid and porphobilinogen after using 2 months ACF mask, may be due slight decreased blood lead level and improved the erythrocytes δ-ALAD activity.

Hematological parameters such as Hb (P < 0.05, 13.42%), PCV (P < 0.05, 7.23%), MCV (P < 0.05, 1.9%) were significantly increased and total WBC count (P < 0.05, − 5.18%) was significantly decreased after using 2 months ACF mask as compared to before using mask of battery manufacturing workers (Table 2 and Fig. 2).

Table 2.

Before and after using 2 months activated carbon fabric mask hematological parameters of battery manufacturing workers

Sr. no.	Parameters	Before using mask (N = 37)	After using mask (N = 37)
1.	Hb (gm/dl)	11.62 ± 1.76 (8.3–14.5)	13.18 ± 1.85*** (8.9–16.7)
2.	HCT or PCV (%)	40.39 ± 4.93 (31.3–54.7)	43.31 ± 3.9*** (35.2–55.1)
3.	MCV (fL)	80.8 ± 7.23 (59–89)	82.34 ± 6.99*** (60.2–90.3)
4.	MCH (pg)	26.7 ± 3.0 (18.3–33.6)	26.3 ± 2.77• (19.2–35.6)
5.	MCHC (gm/dl)	33.0 ± 0.96 (29.8–34.9)	32.64 ± 1.31• (30.8–35.7)
6.	RBC count (million/μl)	4.87 ± 0.63 (3.1–6.4)	4.85 ± 0.68• (3.1–6.7)
7.	WBC count (/cumm)	7.33 ± 1.51 (4.9–11.3)	6.95 ± 1.32* (4.8–9.5)

Figures indicate Mean ± SD values and those in parenthesis are range of values

***P < 0.001, **P < 0.01, *P < 0.05, •Non-significant as compared with before using ACF masks

Fig. 2.

Percentage change of haematological parameters after 2 months using activated carbon fabric mask with respect to before using mask of battery manufacturing workers. Hb haemoglobin, PCV pack cell volume, MCV mean corpuscular volume, MCH mean corpuscular hemoglobin, MCHC mean corpuscular hemoglobin concentration, RBC red blood cells count and WBC white blood cells

Increased blood lead level effects on the hematopoietic system have been well documented in both humans and animals. Leads inhibits heme biosynthesis enzymes, globulin chain formation, reduce the iron absorption, decreases erythropoietin hormone and affects erythrocyte formation, inhibit membrane-bound Na+/K+ -ATPase and decreases erythrocyte survival, which results the decreased heme pool and finally reduce the hemoglobin concentration in blood. Decreased hemoglobin production, coupled with an increase in erythrocyte destruction, results in a hypochromic, normocytic anemia with associated reticulocytosis [2]. Decreased hemoglobin and anemia have been observed in lead exposed workers. Inhibition of heme biosynthesis and reduction of heme pool not only affects the erythropoietic system but also nervous, renal and hepatic systems [2, 15].

After using 2 month ACF respiratory masks, we have observed significant improvement in hematological parameters. Therefore, the regular using this ACF mask will be beneficial to prevent the absorption of lead and its effects on hematopoietic system.

Conclusion

The ACF mask is beneficial to some extent in bringing down the blood lead level, improves the δ-ALDH activity, decreases the urinary excretion of δ-ALA, PBG and improve the hematological parameters. Therefore, the regular using of Activated carbon fabric mask is beneficial to prevent the lead absorption and its adverse effects on human health.

Funding

The funds and the all research facilities are provided by the Krishna Institute of Medical Sciences “Deemed To Be University”, Karad.

Compliance with Ethical Standards

Conflict of interest

The authors declare no conflicts of interest.

Ethical Approval

Ethics approval of this research project was obtained from Institutional Ethics Committee of Krishna Institute of Medical Sciences “Deemed To Be University” Karad and all research work has been completed in same institute.

Informed Consent

The written informed consent is obtained from all the participations in this study.