DSpace at VNU: Exposure assessment of lead to workers and children in the battery recycling craft village, Dong Mai, Vietnam

J Mater Cycles Waste Manag DOI 10.1007/s10163-013-0159-0 SPECIAL FEATURE: ORIGINAL ARTICLE End-of-Life Vehicle (ELV) Recycling Exposure assessment of lead to workers and children in the battery recycling craft village, Dong Mai, Vietnam Takako Noguchi • Takaaki Itai • Nguyen Minh Tue • Tetsuro Agusa • Nguyen Ngoc Ha • Sawako Horai • Pham Thi Kim Trang • Pham Hung Viet Shin Takahashi • Shinsuke Tanabe • Received: 19 January 2013 / Accepted: 19 June 2013 Ó Springer Japan 2013 Abstract Human exposure to lead (Pb) due to uncontrolled Pb-acid battery recycling has been an environmental health issue in newly developed industrial regions We conducted a human monitoring survey in Dong Mai, a battery recycling village in Vietnam, to assess exposure status to Pb Lead level was measured in hair, blood and urine samples of residents in Dong Mai and two reference sites during years spanning 2007–2011 In Dong Mai, Pb levels in three matrixes were significantly higher than those in reference sites Blood Pb levels of all adults and children exceeded 10 lg/dL, the Centers for Disease Control and Prevention definition of an elevated blood Pb level Clear increase of urinary d-aminolevulinic acid (ALA) level with increasing blood Pb level indicated disruption of heme synthesis One adult exceeded 100 lg/dL of blood Pb, where encephalopathy is of concern The blood Pb levels achieved various toxic effect threshold values, and elevated blood Pb was not limited to recycling workers, but was also in children and women of reproductive age Serious T Noguchi Á T Itai (&) Á N M Tue Á T Agusa Á N N Ha Á S Takahashi Á S Tanabe Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan e-mail: itai@sci.ehime-u.ac.jp N M Tue Á P T K Trang Á P H Viet Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Vietnam National University, T3 Building, 334 Nguyen Trai Street, Thanh Xuan District, Hanoi, Vietnam S Horai Recycling-oriented Environmental Science, Department of Regional Environment, Faculty of Regional Sciences, Tottori University, 4-101 Koyama-cho Minami, Tottori, Tottori 680-0945, Japan pollution status of Dong Mai village suggests an importance of further monitoring surveys in various developing Asian countries Keywords Pb battery Á Recycling Á Vietnam Á Risk assessment Á Lead Introduction Lead poisoning remains one of the serious environmental problems in the world, due to prevalent environmental and occupational exposures Lead-acid battery recycling has become a widespread activity in many developing countries [1], and it is an important source of Pb releasing into the environment The hazards of battery recycling have been reported in a series of studies on workers, their families and the environment of various developing countries [2] Vietnam recorded the eighth highest economic growth in Asia [3], and has high resource demands In Vietnam, so called ‘‘craft village’’, which is defined as rural villages with existing craft and non-farming activities drawing the participation of at least 30 % of all households and making at least 50 % of the village’s total income, have greatly contributed to increased income and reduced poverty in rural areas It was estimated that ninety waste recycling craft villages are distributed across the country, mainly in the Northern part [4] Although establishment of craft village is an efficient solution to rural economic development, environmental problems are arising because of the rapidly increasing craft production despite investment for infrastructure being still poor Production in some craft villages, such as plastic, lead and metal recycling craft villages, typically leads to dangerous chronic diseases such as cancer and heavy metal intoxication, due to manual 123 J Mater Cycles Waste Manag procedures of recycling and poor understanding of workers about environmental impacts [5] Dong Mai is such a village in the Northern part of Vietnam, and has been recycling Pb-acid battery for the past 40 years A local news report suggested that of 259 households in the village, at least 61 were involved in Pb recycling, totaling more than 500 workers [6] The General Department of Environment’s report in 2008 warned that Dong Mai villagers can lose up to 10 years of their lifespan due to environmental pollution Another report estimated that 71.1 % of residents have mental diseases and 65.6 % have respiratory diseases, and 100 % of workers suffer from chronic Pb poisoning [7] Considering the situation in Dong Mai, quantitative assessment of exposure status in the village residents is necessary In this study, human exposure to Pb was assessed in a Pb-acid battery recycling site in Dong Mai We have carried out sampling surveys in Dong Mai and two reference sites since 2007 Screening of Pb levels in residents was conducted via analysis of scalp hair, blood and urine Health risk for residents was assessed by comparing blood Pb level to the epidemiologically suggested threshold values of Pb intoxication Urinary d-aminolevulinic acid (ALA) was measured as a biomarker of Pb-induced anemia These surveys aim to elucidate exposure status and health risk, as well as toxicological implications related to battery recycling Materials and methods Study sites Dong Mai village (hereafter DM) in Van Lam district, Hung Yen province, Vietnam was chosen as a study site DM is a small Pb-acid battery recycling craft village with approximately 2300 residents Several hundred tons of waste batteries were transported to DM every month, and the estimated monthly production volume of Pb ingots was 250 tons Most business was family-based and batteries were recycled in the backyard of each house Urban control samples were collected from Hanoi city (hereafter HN), the capital city of Vietnam, in 2008, whereas rural control samples were collected from Duong Quang village (hereafter DQ) in 2010 and 2011 Distances to the reference sites from DM were ca 26 km and km, respectively Sample collection The primary screening surveys were conducted in DM and HN in September 2007 and 2008 (hereafter ‘‘first survey’’), whereas continued monitoring were conducted in DM and 123 DQ in January 2010 and 2011 (hereafter ‘‘second survey’’) In both surveys, scalp hair, blood and urine were collected from the residents Cumulative participants of the first survey were 49 and 20 in DM and HN, respectively In the second survey, cumulative participants were 93 (including 23 children from to 18 years old) and 71 (including children) in DM and DQ, respectively (Table 1) Sex, age, height and weight measurements, occupation, smoking and drinking habitats, hair length and residents time were recorded, and informed consents were obtained from all donors All samples were kept in gel ice immediately after collection and then sent to our laboratory in Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, and frozen at 20 °C The frozen samples were air transported with gel ice to the Environmental Specimen Bank (es-Bank) at Center for Marine Environmental Studies (CMES), Ehime University, Japan and stored at -25 °C until analysis [8] Chemical analysis of elements Human hair samples were washed in an ultrasonic bath with 0.3 % of polyoxyethylene lauryl ether and subsequently dried for 12 h at 80 °C [9] Hair samples were digested in a mixture of concentrated HNO3 and 50 % HF (5:1) in Teflon vials using a microwave system (Ethos D, Milestone S.r.l., Sorisole, BG, Italy) Human blood and urine samples were digested in HNO3 with the microwave system Hot plate digestion was also employed for blood analyses at 200 °C for h in Teflon vials The level of Pb was measured using an inductively coupled plasma mass spectrometer (ICP-MS; Agilent 7500cx, Agilent Technologies, Tokyo, Japan) Rhodium was used for internal standards for correction of matrix effects and instrumental drift in ICP-MS measurements Accuracy and precision of measurements was assessed by analyzing standard reference materials: NIES No human hair and NIES No 18 human urine provided by National Institute for Environmental Studies (NIES), Japan and IAEA A-13 bovine blood provided by International Atomic Energy Agency (IAEA), Austria The recoveries of elements were in the range of 87–106 % of certified value Urinary d-aminolevulinic acid analysis Determination of urinary d-aminolevulinic acid (ALA) was carried out by SRL Inc., Tokyo, Japan A brief procedure of analysis was as follows The urine sample was mixed with in acetyl acetone, ethanol and formaldehyde solution and boiled The fluorescent derivative of ALA was analyzed by high performance liquid chromatography coupled with a fluorometer J Mater Cycles Waste Manag Table Median and range of Pb concentration in hair (lg/g), blood (lg/dL) and urine (ng/g) in residents of DM and reference sites in first and second surveys Dong Mai Hair (first survey) Blood (first survey) Blood (Second survey) Urine (first survey) 51 (2.5–2300) n = 49 20 (5.5–110) n = 49 34 (14–122) n = 93 24 (3.1–200) n = 49 Adult male 120 (2.5–2300) n = 16 35 (14–110) n = 16 43 (23–122) n = 30 56 (12–200) n = 16 Adult female (n = 16) Child (n = 16) 48 (19–220) n = 33 N.A 20 (5.5–71) n = 33 N.A 36 (14–87) n = 40 29 (17–48) n = 23 20 (3.1–150) n = 33 N.A 1.9 (0.80–5.5) n = 20 3.3 (1.9–6.3) n = 20 3.3 (1.0–11) n = 71 2.7 (0.79–6.0) n = 20 3.0 (0.96–4.3) n = 4.1 (2.3–6.3) n = 4.2 (2.3–10) n = 24 2.7 (1.5–6.0) n = Hanoi (first survey) and Duong Quang (second survey) Adult male (n = 16) Adult female (n = 16) 1.7 (0.80–5.5) n = 11 2.8 (1.9–4.5) n = 11 2.7 (1.0–11) n = 42 2.8 (0.79–5.8) n = 11 Child (n = 16) N.A N.A 2.9 (2.0–5.0) n = N.A N.A not available Statistical analysis All statistical analysis was performed with Statcel (Seiun Inc., Tokyo, Japan) and R software (version 2.14.0) The Mann–Whitney U test was employed to verify significant differences between DM and HN or DQ The Steel– Dwass’s test was used to determine the difference in blood Pb levels among six groups, i.e., adult male in DM, adult female in DM, male children in DM, female children in DM, adult male in DQ, and adult female in DQ A p value of less than 0.05 was considered as an indication of statistical significance, unless otherwise mentioned The data below the limit of detection were included in the statistical evaluation as an estimated 50 % of the detection limit value Results Pb levels in hair, blood, and urine The Pb levels in hair were determined only in the first survey population The Pb level in hair was extremely high in DM compared to HN (Table 1) The median value ratio of Pb between DM and HN were 27 The Pb level in blood was determined in both the first and the second surveys Among the first survey population, the Pb levels in DM were higher than HN (p \ 0.001) (Table 1), with the median value ratio of Pb being 6.1 Among the second survey population, blood Pb levels of 93 residents in DM were statistically higher than in DQ (p \ 0.001) (Fig 1) The median value ratio of blood Pb between DM and DQ was 11 In DM, blood Pb levels in the second survey population were significantly higher than that of first survey population (p \ 0.001) Among the second survey population, blood Pb levels of adult males were higher than those of females in DM Fig The box-whisker plot of blood Pb levels among six groups Only the data obtained from the second survey were used The horizontal line indicates the median, the box covers the 25th–75th percentiles and the maximum length of each whisker is 1.5 times the interquartile range Points outside this show up as outliers Groups with the same letters not have significantly different levels in Steel–Dwass’s test for multiple comparisons (p \ 0.01), whereas gender difference was insignificant among residents in DQ (Fig 1) Blood Pb levels of 23 children in DM were also higher than for residents in DQ (p \ 0.01) (Fig 1) In DM, blood Pb levels of children were comparable to those in females The median value ratio of blood Pb between children in DM and residents in DQ was The trace element levels in urine were determined only in the first survey population In urine, the levels of Pb were significantly higher in DM than in HN (p \ 0.001), with the ratio of median values of Pb being 8.7 123 J Mater Cycles Waste Manag Relationship between blood Pb and urinary ALA The ALA analysis was conducted for the second survey population Urinary ALA levels in DM varied from 0.3 to 71 mg/L in DM, and were significantly higher (p \ 0.001) than those of DQ (0.1–3.0 mg/L) The ALA levels positively correlated with blood Pb levels in DM (p \ 0.001, r = 0.47), whereas these were not correlated in DQ (p [ 0.05, r = -0.19) (Fig 2) Senegalese battery recycling area where 18 children died (mean 56, range 38–81 lg/dL) [1] Gender differences of blood Pb levels provided some information for exposure pathway Males showed higher blood Pb levels than females since they often are more likely to engage in the Pb smelting work, whereas females only dismantled waste batteries It is worth noting that children also have higher level of blood Pb than those found at the reference site Therefore, environmental Pb contamination in DM was not limited to workers, but also local residents like children Discussion Risk assessment for human exposure to Pb among second survey population Exposure level The human monitoring data of this study demonstrated serious contamination by Pb in DM residents The Pb levels of scalp hair in DM were comparable to other seriously contaminated sites, e.g., Singapore (mean 640, range 0.93–3500 lg/g) [10], Poland (mean 150, range 35–290 lg/g) [11] and the West Indies (mean 590, range 51–1500 lg/g) [12] Similar to the scalp hair, blood Pb levels also indicated serious exposure status Because blood Pb levels are a more direct signature of Pb burden in the body than hair, comparison to the other sites is useful to evaluate potential of health effect The blood Pb levels of this study were comparable to those reported in other studies where some health effects are observed, i.e., children in a backyard battery repair shop in Jamaica, where 22 children were hospitalized for Pb poisoning (mean 32, range 31–170 lg/ dL) [13]; hormone disruption of Taiwanese battery workers (mean ± SD: 24 ± 12 lg/dL) [14]; and residents in a Urinary delta-aminolevulinic acid (mg/L) 80 : DM p < 0.001, r = 0.47 : DQ p > 0.05 70 60 50 40 30 20 10 0 50 100 150 Blood Pb (µg/dL) Fig Relationships between urinary ALA and blood Pb levels of the participants in the second survey 123 Health risk of Pb exposure was evaluated by comparing the blood Pb levels to the epidemiologically defined toxic effect thresholds Of the 93 residents, including 23 children, from DM, all had blood Pb levels exceeding the minimum toxic threshold values (10 lg/dL) recommended by The Agency for Toxic Substances and Disease Registry [15] Blood Pb levels greater than this value may induce decreasing activity of heme biosynthesis enzymes and elevating blood pressure Since Pb is a cumulative toxicant that affects multiple body systems, such as neurological, hematological, gastrointestinal, cardiovascular and renal systems, continuous Pb-acid battery recycling could lead to serious health risk among residents Blood Pb levels greater than 100 lg/dL raise concern of encephalopathy [15] One adult corresponded to this blood Pb level, with it as high as 122 lg/dL Actually, this level is comparable to those reported in a serious Pb pollution site in Dakar, Senegal, where 18 children have died, possibly due to Pb exposure [1] The urinary ALA levels supported possible manifestation of toxic effect by the Pb exposure ALA level is an initial compound in the heme synthesis pathway, and its level in urine can be used as the signature of anemia, which is the initial manifestation associated with Pb exposure The inhibition of ALA dehydratase (ALAD) by Pb causes an increase in ALA in plasma, and consequently excretion of ALA in urine [16, 17] Urinary ALA levels increased with blood Pb levels, suggesting that inhibition of ALAD occurred due to high Pb in blood (Fig 2) This clear rising trend, stated from around blood level [ 50 lg/dL, was almost consistent with the trend observed in a previous study [18] Since Pb exposure was not limited to the adults but also children in DM, adverse effects for children are of particular concern Children, with their nervous system in active development, are generally vulnerable to the neurotoxicological affects of Pb Higher gastrointestinal tract uptake ratio and hand-to-mouth behavior enhances risk for J Mater Cycles Waste Manag children [19] The minimum threshold blood Pb level corresponding to adverse health effects are lower than adults [20] The Center for Disease Control and Prevention (CDC) recommends that children’s blood Pb levels greater than 10 lg/dL require further monitoring [21] All 23 children surveyed in DM had levels greater than 10 lg/dL, with a maximum of 48 lg/dL According to the field observation and questionnaire survey, children were not directly involved in the recycling activity in both smelting factory and backyard recycling site Hence, this result suggests two possibilities: 1) the extent of Pb contamination is already widely spread in the village; or 2) children are actually involved in the recycling activity In either case, the situation is serious The current situation in DM is serious, and a more severe situation may probably occur if urgent mitigation activity is not taken up soon Lead is a well-known cumulative toxicant and prenatal Pb exposure can occur not only through current maternal environmental exposures, but also through the mobilization of cumulative maternal bone Pb stocks during pregnancy and lactation [22, 23] Additionally, maternal Pb burden causes risk for the following generation, even after improvement of the contaminated environment [24] Seventy-two percent of the women in DM were in reproductive age, and their median blood Pb level was 36 lg/dL, which may be associated with adverse birth outcomes [25–27] All the facts strongly suggest that medical treatment such as chelating therapy is urgently needed in the village, DM [28] non-government organization (Blacksmith Institute) succeeded in reducing symptoms of Pb poisoning in humans by removal of soil from the high Pb region that exceeded Pb content [1,000 mg/kg [29] We assume that the same treatment may be also effective in DM The estimated area in which the soil Pb level exceeds 1000 mg/kg in Dong Mai is ca 10,000 m2 Hence, ca 2,000 m3 of soil should be removed, assuming that effective removal depth is 20 cm In the Senegal case, the budget to complete soil removal was USD 200,000 to remove 3,700 m3 soil in years In order to achieve such a mitigation program, establishment of a cooperative framework by national and local governments and non-government organizations is urgently needed Finally, the result of this study is an alarm that similar situations may occur in other craft villages in Vietnam, and also in other Asian developing countries Since transport of waste material is not limited to national scale, the help of developed countries is important to improve the material recycling system in developing Asian countries Acknowledgments This study was supported by Grants-in-Aid for Scientific Research (A) (No 25257403), ‘‘Global COE Program’’ and ‘‘Project for the Encouragement of Science/Math-Oriented University Students’’ from the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT) and Japan Society for the Promotion of Science (JSPS) and Waste Management Research Grant (K123001) from the Ministry of Environment, Japan We also acknowledge the approval of the Photon Factory Program Advisory Committee (Proposal No 2009G632) The success of this investigation was thanks to the support and collaboration of donors and member of the health authorities in Dong Mai and Duong Quang village Conclusion References Serious contamination of Pb was confirmed in the Pb-acid battery recycling site in Dong Mai village, Northern part of Vietnam The blood Pb levels achieved various toxic effect threshold values, and apparent enrichment in blood was not limited to recycling workers, but was also in children and women of reproductive age The manifestation of Pb poisoning was apparent by clear elevation of urinary ALA levels Considering the widespread Pb contamination in the village scale, not only should further monitoring be continued, but providing a pollution control solution is also needed Since the major exposure pathway is likely inhalation and/or ingestion of heavily contaminated soil and dust in suspension, soil removal is an important solution to prevent residents from further exposure A preliminary screening using field portable X-ray fluorescence spectroscopy indicated that Pb 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recycling Pb-acid battery for the past 40 years A local news report suggested that of 259 households in the village, at least 61 were involved in Pb recycling, totaling more than 500 workers [6] The. .. contamination of Pb was confirmed in the Pb-acid battery recycling site in Dong Mai village, Northern part of Vietnam The blood Pb levels achieved various toxic effect threshold values, and apparent