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http://dx.doi.org/10.1007/s43188-021-00093-2

The toxic effects of spent crankcase oil exposures; systematic review and meta-analysis  

Bekibele, Grace Eserophe (World Bank Africa Centre of Excellence in Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt)
Anacletus, Francis Chukwuma (World Bank Africa Centre of Excellence in Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt)
Patrick‑Iwuanyanwu, Kingsley Chukwuemeka (World Bank Africa Centre of Excellence in Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt)
Publication Information
Toxicological Research / v.38, no.2, 2022 , pp. 113-135 More about this Journal
Abstract
The study sought to execute a systematic review and meta-analysis to describe the toxicological implications associated with exposures of humans and laboratory animals to Spent Crankcase Oil (SCO). Databases like PubMed, Scopus, Science Direct, Google Scholar, Web of Science, and PlosOne were searched systematically for all data that assessed the effects of SCO on humans and animals. For each parameter involved in the meta-analysis (those with extractable data), mean, standard deviation, the sample size was extracted for both exposure groups and control. This was then used to compute the standardized mean difference (SMD). Statistical analysis and forest plots were done with RevMan 5.3 software. Twenty-eight (28) studies fulfilled the pre-specified criteria for eligibility. Fourteen (14) of the studies were used for the meta-analysis, which included a total of 1243 subjects from different human epidemiological occupational exposure studies and animal experimental studies. The meta-analysis revealed that SCO exposure caused a significant reduction in the body weight of animals (n=5, SMD; -1.2; 95% CI; (-1.78, -0.67), p=0.0001, I2=22%), and in the red blood cell count (n=5, SMD; -1.28; 95% CI; (-2.18, -0.38, p=0.02); I2=78%) and haemoglobin (n=4, SMD; -1.12, 95% CI; (-2.71, 0.46); p=0.16; I2=89%) in animal models. While there was a significant elevation of the aspartate amino transferase (AST) (n=6, SMD; 0.76; 95%CI; (0.41, 1.11), p=0.0001, I2=89%), alkaline phosphatase (ALP) (n=5, SMD; 1.92; 95% CI; (0.02, 3.83), p=0.05, I2=92%), and creatinine (n=4, SMD=1.56; 95% CI; (0.05, 3.07), p=0.04, I2=90%) concentrations in comparison to the control. On the other hand, there was a non-significant effect on the alanine amino transferase (ALT) (n=5, SMD; 1.13; 95% CI; (-0.37, 2.62); p=0.14; I2=92%), urea (n=4, SMD; 1.23; 95% CI; (-1.18, 3.65), p=0.32, I2=94%), packed cell volume (PCV) (n=5, SMD; 0.10; 95% CI; (-0.36, 0.56), p=0.67; I2=47%); and the haemoglobin (n=6; SMD; -0.74; 95% CI; (-1.73, 0.26), p=0.15; I2=89%) concentrations. Oxidative stress, heavy metals bioaccumulation, immunotoxic, genotoxic, and carcinogenic effects were also in the list of findings. The toxicological implications associated with SCO exposure points to the need for immediate establishment of policies that regulate the disposal of spent crankcase oil in the environment.
Keywords
Spent crankcase oil; Lubricating oil; Polycyclic aromatic hydrocarbons; Heavy metals;
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1 Van Donkelaar P (1990) Environmental effects of crankcase-and mixed-lubrication. Sci Total Environ 92:165-179   DOI
2 Mckee RH, Plutnick RT (1989) Carcinogenic potential of gasoline and diesel engine oils. Toxicol Sci 13:545-553. https://doi.org/10.1093/toxsci/13.3.545   DOI
3 Ochiogu IS, Ihedioha JI, Anya KO, Nwoye JCS (2009) The reproductive performance of albino rats given drinking water contaminated with varied low percentages of used engine lubricating oil. In: Proceedings of the 34th. Annual conference of the Nigerian society for animal production (NSAP). pp 167-171
4 Grimmer G, Dettbarn G, Brune H et al (1982) Quantification of the carcinogenic effect of polycyclic aromatic hydrocarbons in used engine oil by topical application onto the skin of mice. Int Arch Occup Environ Health 50:95-100. https://doi.org/10.1007/BF004 32496   DOI
5 Ihedioha JI, Iwuogo MU, Ihedioha TE (2009) Haematological and clinical chemistry findings associated with sub-acute contamination of drinking water with varied low percentages of used engine oil. Comp Clin Path 18:169-176. https://doi.org/10.1007/s00580-008-0778-3   DOI
6 Lefcort H, Hancock KA, Maur KM, Rostal DC (1997) The effects of used motor oil, silt, and the water mold Saprolegnia parasitica on the growth and survival of mole salamanders (genus Ambystoma). Arch Environ Contam Toxicol 32:383-388. https://doi.org/10.1007/s002449900200   DOI
7 Mohamed SH, EL-Leithy EMM, Ghandour RA, Galal MK (2019) Molecular, biochemical and histopathological studies on the ameliorative effect of vitamin C on the renal and muscle tissues of Nile tilapia fish (Oreochromis niloticus) affected by the usage of engine oil. Aquac Res 50:3357-3368. https://doi.org/10.1111/are.14294   DOI
8 Ekeh FN, Ekechukwu NE, Atama CI, Atta IC (2010) Haematology profile of albino rats given feed and water contaminated with varied concentrations of used engine oil. Animal Res Int 7:1229-1235. https://doi.org/10.1016/0048-9697(90)90328-R   DOI
9 Ezeonu CS, Onwurah INE, Oje OA (2012) Comprehensive perspectives in bioremediation of crude oil contaminated environments. Ed by Dr Laura Romero-Zeron Introd to Enhanc Oil Recover Process bioremediation oil-contaminated sites InTech. Croatia. pp 143-184 ISBN: 978-953-51-0629-6
10 Brinkman DW, Gottlieb M, Koelbel K (1982) Used motor oil passes environmental problem. Oil Gas J 80(32):163-165
11 Ssempebwa JC, Carpenter DO, Yilmaz B et al (2004) Waste crankcase oil: an environmental contaminant with potential to modulate estrogenic responses. J Toxicol Environ Health Part A 67:1081-1094. https://doi.org/10.1080/15287390490452308   DOI
12 Valko M, Cj R, Moncol J et al (2006) Free radicals, metals and antioxidants in oxidative stress-induced cancer. Chem Biol Interact 160:1-40. https://doi.org/10.1016/j.cbi.2005.12.009   DOI
13 Achuba FI (2018) Modulation of crude oil induced alteration of oxidative stress indices in rat by red palm oil. J Appl Sci Environ Manag 22:929-932. https://doi.org/10.4314/jasem.v22i6.15   DOI
14 Jankowski M, Dyszkiewicz-Konwinska M, Magas M, et al (2018) Haematopoiesis: living in the shadow of stem cell differentiation. J Biol Regul Homeost Agents 32(1):1-6. PMID:29504358
15 Zaki MS, Mostafa SO, Fawzi OM et al (2009) Clinicopathological, biochemical and microbiological change on grey mullet exposed to cadmium chloride. Am J Agric Environ Sci 5:20-23 ISSN:1818-6769
16 Cvengros J, Liptaj T, Pronayova N (2017) Study of polyaromatic hydrocarbons in current used motor oils. Int J Petrochemical Sci Eng. https://doi.org/10.15406/ipcse.2017.02.00060   DOI
17 Ahmed YH, Bashir DW, Abdel-moneam DA et al (2019) Histopathological, biochemical and molecular studies on the toxic effect of used engine oil on the health status of Oreochromis niloticus. Acta Histochem 121:563-574. https://doi.org/10.1016/j.acthis.2019.04.005   DOI
18 Lu ST, Kaplan IR (2008) Characterization of motor lubricating oils and their oil-water partition. Environ Forensics 9:295-309. https://doi.org/10.1080/15275920802119441   DOI
19 Sibomana I, Good NA, Hellman PT et al (2019) Acute dermal toxicity study of new, used and laboratory aged aircraft engine oils. Toxicol Reports 6:1246-1252. https://doi.org/10.1016/j.toxrep.2019.11.010   DOI
20 Omorowa F, Agu K, Okolie N et al (2015) Influence of spentengine oil on hematology, renal and liver status of auto-mechanics of Benin-City, Nigeria. J Appl Sci Environ Manag 19:383. https://doi.org/10.4314/jasem.v19i3.6   DOI
21 Pruell RJ, Quinn JG (1988) Accumulation of polycyclic aromatic hydrocarbons in crankcase oil. Environ Pollut 49:89-97. https://doi.org/10.1016/0269-7491(88)90242-4   DOI
22 Naiho AO, Aloamaka EO, Nwochi CN (2014) Effect of zidovudine on the liver function of adult albino wistar rats. Int J Basic Appl Innov Res 3:95-99 ISSN:2315-5388
23 Drotman RB, Lawhorn GT (1978) Serum enzymes as indicators of chemically induced liver damage. Drug Chem Toxicol 1:163-171. https://doi.org/10.3109/01480547809034433   DOI
24 Subramoniam A, Pushpangadan P et al (1999) Development of phytomedicines for liver disease. Indian J Pharmacol 31:166 ISSN:0253-7613
25 Muriel P, Garciapina T, Perez-Alvarez V, Mourelle M (1992) Silymarin protects against paracetamol-induced lipid peroxidation and liver damage. J Appl Toxicol 12:439-442. https://doi.org/10.1002/jat.2550120613   DOI
26 Goyer RA, Clarkson TW (1996) Toxic effects of metals. Casarett Doull's Toxicol basic Sci poisons 5:696-698
27 Akanji MA, Olagoke OA, Oloyede OB (1993) Effect of chronic consumption of metabisulphite on the integrity of the rat kidney cellular system. Toxicology 81:173-179. https://doi.org/10.1016/0300-483X(93)90010-P   DOI
28 Khanna S, Dogra RKS (2003) Immunotoxicological effects of dermal application of scum of waste crankcase oil in mice. Indian J Exp Biol 41:592-597 PMID:15266905
29 Omoregie E, Ufodike BC (2000) Effects of water soluble fractions of crude oil on growth of the Nile tilapia, Oreochromis niloticus (L.). Bull Environ Contam Toxicol 64:601-605. https://doi.org/10.1007/s001280000045   DOI
30 Moles A, Rice SD (1983) Effects of crude oil and naphthalene on growth, caloric content, and fat content of pink salmon juveniles in seawater. Trans Am Fish Soc 112:205-211. https://doi.org/10.1577/1548-8659(1983)112-205:EOCOAN-2.0.CO;2   DOI
31 Ogali RE, Osuji LC, Ayodele O (2007) Acute toxicity of the water-soluble fraction of spent lubricating oil on the african catfish Clarias gariepinus. Chem Biodivers 4:2755-2765. https://doi.org/10.1002/cbdv.200790224   DOI
32 Arise RO, Tella AC, Akintola AA et al (2012) Toxicity evaluation of crankcase oil in rats. Excli J 11:219-225. https://doi.org/10.17877/DE290R-5759   DOI
33 Upshall C, Payne JF, Hellou J (1993) Induction of mfo enzymes and production of bile metabolites in rainbow trout (Oncorhynchus mykiss) exposed to waste crankcase oil. Environ Toxicol Chem 12:2105-2112. https://doi.org/10.1002/etc.56201 21118   DOI
34 Eastin WC, Hoffman DJ, O'Leary CT (1983) Lead accumulation and depression of δ-aminolevulinic acid dehydratase (ALAD) in young birds fed automotive waste oil. Arch Environ Contam Toxicol 12:31-35. https://doi.org/10.1007/BF010 54998   DOI
35 Ali F, El-Shehawi AM, Seehy MA (2008) Micronucleus test in fish genome: a sensitive monitor for aquatic pollution. African J Biotechnol 7(5): 606-612. ISSN: 1684-5315
36 Ramesh A, Archibong AE, Niaz MS (2010) Ovarian susceptibility to benzo [a] pyrene: tissue burden of metabolites and DNA adducts in F-344 rats. J Toxicol Environ Heal Part A 73:1611-1625. https://doi.org/10.1080/15287394-2010.514225   DOI
37 Rengarajan T, Rajendran P, Nandakumar N et al (2015) Exposure to polycyclic aromatic hydrocarbons with special focus on cancer. Asian Pac J Trop Biomed 5:182-189. https://doi.org/10.1016/s2221-1691(15)30003-4   DOI
38 Kamal A, Malik RN (2012) Hematological evidence of occupational exposure to chemicals and other factors among auto-repair workers in Rawalpindi, Pakistan. Osong public Heal Res Perspect 3:229-238. https://doi.org/10.1016/j.phrp.2012.10.003   DOI
39 Karahalil B, Burgaz S, Ficsek G, Karakaya AE (1998) Biological monitoring of young workers exposed to polycyclic aromatic hydrocarbons in engine repair workshops. Mutat Res Toxicol Environ Mutagen 412:261-269. https://doi.org/10.1016/s1383-5718(97)00197-6   DOI
40 Makpo JK (2018) Effects of water-soluble fractions of used crankcase oil on some physiological parameters of the Nile Tilapia (Oreochromis Niloticus). University of Jos, Jos. http://hdl.handle.net/123456789/2733
41 Luo T, Shen M, Zhou J et al (2019) Chronic exposure to low doses of Pb induces hepatotoxicity at the physiological, biochemical, and transcriptomic levels of mice. Environ Toxicol 34:521-529. https://doi.org/10.1002/tox.22706   DOI
42 Rauckyte T, Hargreaves DJ, Pawlak Z (2006) Determination of heavy metals and volatile aromatic compounds in used engine oils and sludges. Fuel 85:481-485. https://doi.org/10.1016/j.fuel.2005.08.004   DOI
43 Payne JF, Martins I, Rahimtula A (1978) Crankcase oils: are they a major mutagenic burden in the aquatic environment? Science 200:329-330. https://doi.org/10.1126/science.635591   DOI
44 Sas B (1989) Secondary copper deficiency in cattle caused by molybdenum contamination of fodder: a case history. Vet Hum Toxicol 31:29-33 PMID: 2711604
45 Incardona JP (2017) Molecular mechanisms of crude oil developmental toxicity in fish. Arch Environ Contam Toxicol 73:19-32. https://doi.org/10.1007/s00244-017-0381-1   DOI
46 Gulati K, Ray A (2009) Immunotoxicity. Handbook of toxicology of chemical warfare agents. Elsevier, Amsterdam, pp 595-609
47 Orisakwe OE, Akumka DD, Njan AA et al (2005) Hepatotoxic and haematological effects of Nigerian Bonny light crude oil in male albino rats. Toxicol Environ Chem 87:215-221. https://doi.org/10.1080/102772240400026823   DOI
48 Byrne CJ, Calder JA (1977) Effect of the water-soluble fractions of crude, refined and waste oils on the embryonic and larval stages of the quahog clam Mercenaria sp. Mar Biol 40:225-231. https://doi.org/10.1007/BF00390878   DOI
49 Hoffman DJ, Eastin WC, Gay ML (1982) Embryotoxic and biochemical effects of waste crankcase oil on birds' eggs. Toxicol Appl Pharmacol 63:230-241. https://doi.org/10.1016/0041-008X(82) 90045-X   DOI
50 Blakley BR, Brockman RP (1976) Lead toxicosis in cattle in Saskatchewan. Can Vet J 17:16 PMID:1260635
51 Patrick-Iwuanyanwu K, Ogwe GO, Onwuka FC (2010) The hepatotoxic effects of the water-soluble fraction of spent lubricating oil in Wistar albino rats. Internet J Toxicol 7(2):1-17
52 Takeshima N, Sozu T, Tajika A et al (2014) Which is more generalizable, powerful and interpretable in meta-analyses, mean difference or standardized mean difference? BMC Med Res Methodol 14:30. https://doi.org/10.1186/1471-2288-14-30   DOI
53 Vemot EH, Drew RT, Kane ML (1990) Acute toxicologic evaluation of used motor oil. J Am Coll Toxicol 1:147. https://doi.org/10.1177/109158189000100270   DOI
54 Alimba CG, Bakare AA, Aina OO (2012) Liver and kidney dysfunction in wistar rats exposed to municipal landfill leachate. Resour Environ 2:150-163. https://doi.org/10.5923/j.re.2012.0204.04   DOI
55 Bender ML, Frantzen M, Vieweg I et al (2016) Effects of chronic dietary petroleum exposure on reproductive development in polar cod (Boreogadus saida). Aquat Toxicol 180:196-208. https://doi.org/10.1016/j.aquatox.2016.10.005   DOI
56 Hassan R, Ismail NJ, Ismail AR et al (2014) A lab scale study on the effects of waste lubricating oil to red Tilapia Oreochromis sp. Juveniles Borneo J Resour Sci Technol 4:1-8
57 Schoket B, Hewer A, Grover PL, Phillips DH (1989) 32P-postlabelling analysis of DNA adducts in the skin of mice treated with petrol and diesel engine lubricating oils and exhaust condensates. Carcinogenesis 10:1485-1490. https://doi.org/10.1093/carcin/10.8.1485   DOI
58 Oswktter GD, Buck WMB, Lloyd WE (1973) Epidemiology of lead poisoning in cattle-a five-year study in Iowa. Clin Toxicol 6:367-376. https://doi.org/10.3109/15563 65730 89905 37   DOI
59 Hooijmans CR, Rovers MM, De Vries RBM et al (2014) SYRCLE's risk of bias tool for animal studies. BMC Med Res Methodol 14:43. https://doi.org/10.1186/1471-2288-14-43   DOI
60 Ayoola SO, Akaeze CO (2012a) Genotoxic Evaluation and Toxicity of Spent Engine Oil on Clarias gariepinus. Res J Environ Toxicol 6(4):133-141. https://doi.org/10.3923/rjet. 2012. 133. 141   DOI
61 Granella M, Clonfero E (1993) Urinary excretion of 1-pyrenol in automotive repair workers. Int Arch Occup Environ Health 65:241-245. https://doi.org/10.1007/BF00381197   DOI
62 Akintunde WO, Olugbenga OA, Olufemi OO (2015) Some adverse effects of used engine oil (common waste pollutant) on reproduction of male Sprague Dawley Rats. Open Access Maced J Med Sci 3:46. https://doi.org/10.3889/oamjms.2015.035   DOI
63 Baldwin RW, Cunningham GJ, Pratt D (1964) Carcinogenic action of motor engine oil additives. Br J Cancer 18:503. https://doi.org/10.1038/bjc.1964.56   DOI
64 Clonfero E, Nardini B, Marchioro M et al (1996) Mutagenicity and contents of polycyclic aromatic hydrocarbons in used and recycled motor oils. Mutat Res Genet Toxicol 368:283-291. https://doi.org/10.1016/S0165-1218(96)90070-1   DOI
65 Hewstone RK (1994) Health, safety and environmental aspects of used crankcase lubricating oils. Sci Total Environ 156:255-268. https://doi.org/10.1016/0048-9697(94)90192-9   DOI
66 Sridhar MKC, Jegede A, Oluborode UZ (2017) Waste management policy and implementation in Nigeria. Natl J Adv Res 3:23-35 ISSN:2455-216X
67 Vazquez-Duhalt R (1989) The purpose of this review is to gain an insight into the production and fate of used crankcase oil; the effects of dispersion and spillage of used motor oil on the soil and aquatic environment; and the environmental importance of waste oil combustion. Sci Total Environ 79:1-23. https://doi.org/10.1016/0048-9697(89)90049-1   DOI
68 Ingram AJ, Scammells DV, May K (1994) An investigation of the main mutagenic components of a carcinogenic oil by fractionation and testing in the modified Ames assay. J Appl Toxicol 14:173-179. https://doi.org/10.1002/jat.2550140305   DOI
69 Government of Canada. (1994) Priority Substances List Assessment Report on Waste Crankcase oils (WCOs). Ottawa, Ontario. p 39
70 Lale OO, Ezekwe IC, Lale NES (2014) Effect of spent lubricating oil pollution on some Chemical parameters and the growth of Cowpeas (Vigna unguiculata Walpers). Res Environ 4:173-179. https://doi.org/10.5923/j.re.20140403.06   DOI
71 Brocksen RW, Bailey HT (1973) Respiratory response of juvenile chinook salmon and striped bass exposed to benzene, a watersoluble component of crude oil. In: International oil spill conference. pp 783-791. https://doi.org/10.7901/2169-3358-1973-1-783   DOI
72 Ofunne GC, Maduako AU, Ojinnaka CM (1990) High temperature oxidation stability of automotive crankcase oils and their base oils. Tribol Int 23:407-412   DOI
73 Udofia U (2010) Acute toxicity of Qua Iboe light crude oil on a fresh water fish, Oreochromis niloticus. Glob J Pure Appl Sci 16(3):295-302. https://doi.org/10.4314/gjpas.v16i3.62854   DOI
74 Smith RL, Cameron JA (1979) Effect of water soluble fraction of Prudhoe Bay crude oil on embryonic development of Pacific herring. Trans Am Fish Soc 108:70-75. https://doi.org/10.1577/1548-8659(1979)108-70:EOWSFO-2.0.CO;2   DOI
75 Awoyinka OA, Atulomah E, Atulomah NOS (2011) Comparative effects of crude oil on juveniles Clarias gariepinus and Clarias anguillaris. Int J Fish Aquac 3:239-243. https://doi.org/10.5897/IJFA11.052   DOI
76 Kayode SJ, Chidimma UI, Alwell EE et al (2014) Response of some antioxidant parameters in post juveniles of Clarias gariepinus after exposure to Nigerian crude oil (Forcados, Bonny Light and Qua-Iboe). Pak J Biol Sci 17:1225-1230. https://doi.org/10.3923/pjbs.2014.1255.1230   DOI
77 Desurmont M (1983) Carcinogenic effect of metals. La Sem des Hop organe fonde par l'Association d'enseignement Med des Hop Paris 59:2097-2099 PMID 6312579
78 Ercal N, Gurer-Orhan H, Aykin-Burns N (2001) Toxic metals and oxidative stress part I: mechanisms involved in metal-induced oxidative damage. Curr Top Med Chem 1:529-539. https://doi.org/10.2174/1568026013394831   DOI
79 Stohs SJ, Bagchi D, Hassoun E, Bagchi M (2000) Oxidative mechanisms in the toxicity of chromium and cadmium ions. J Environ Pathol Toxicol Oncol 19:201-213 PMID:10983887
80 Aravindakshan J, Paquet V, Gregory M et al (2004) Consequences of xenoestrogen exposure on male reproductive function in spottail shiners (Notropis hudsonius). Toxicol Sci 78:156-165. https://doi.org/10.1093/toxsci/kfh042.Epub   DOI
81 ATSDR (1997) Toxicological Profile for Used Mineral-Based Crankcase Oil. Agency for Toxic Substances and Disease Registry. Atlanta, Georgia. https://www.atsdr.cdc.gov/toxprofiles/tp102.html
82 Babalola SO, Ajani OS, Oni AA (2016) Semen characteristics and testicular biometry of Swiss albino mice treated with water soluble fractions of spent engine oil. Int J Biol Chem Sci 10:211. https://doi.org/10.4314/ijbcs.v10i1.16   DOI
83 Babalola SO, Oni AA (2018) Hepatotoxic and renal effects of the water soluble fractions of spent engine oil in Swiss albino mice. Int J Biol Chem Sci 12:650. https://doi.org/10.4314/ijbcs.v12i2.3   DOI
84 Olalekan Wasiu A, Ojo OA, Ogundipe OO (2015) Some adverse effects of used engine oil (Common waste pollutant) on reproduction of male sprague dawley rats. Maced J Med Sci 3:46-51. https://doi.org/10.3889/oamjms.2015.035   DOI
85 Ng SP, Conklin DJ, Bhatnagar A et al (2009) Prenatal exposure to cigarette smoke induces diet-and sex-dependent dyslipidemia and weight gain in adult murine offspring. Environ Health Perspect 117:1042-1048. https://doi.org/10.1289/ehp.0800193   DOI
86 Johnston DE (1999) Special considerations in interpreting liver function tests. Am Fam Physician 59:2223. PMID:10221307
87 Obini U, Okafor C, Afiukwa J (2013) Determination of levels of polycyclic aromatic hydrocarbons in soil contaminated with spent motor Engine oil in Abakaliki Auto-Mechanic Village. J Appl Sci Environ Manag. https://doi.org/10.4314/jasem.v17i2.1   DOI
88 Kawamura K, Ng LL, Kaplan IR (1985) Determination of organic acids (C1-C10) in the atmosphere, motor exhausts, and engine oils. Environ Sci Technol 19:1082-1086. https://doi.org/10.1021/es00141a010   DOI
89 Clausen J, Rastogi S (1977) Heavy metal pollution among autoworkers. I. Lead. Occup Environ Med 34:208-215. https://doi.org/10.1136/oem.34.3.208   DOI