Illegal Toxic Waste Dumping: Comparison
View Latest Version
Please note this is a comparison between Version 2 by Lily Guo and Version 4 by Lily Guo.

Poor management of hazardous waste can lead to environmental pollution, injuries, and adverse health risks. Children’s exposure to hazardous waste may cause serious acute and chronic health problems due to their higher vulnerability to the toxic effects of chemicals. 

  • environmental exposure
  • environmental pollution

1. Introduction

Poor hazardous waste management has become a serious issue in developing countries [1][2][3]. Most cities in those nations are rapidly industrializing, leading to a greater generation of hazardous waste [4][5]. There are inadequacies in the implementation of regulations related to hazardous waste treatment and final disposal of hazardous materials, which have posed significant risks to the environment, ecology, and human health [6][7][8]. The impacts of illegal waste dumping vary depending on the scale, source, and waste characteristics [9]. Among the factors that have influenced the hazardous waste management practice in developing countries are disposal technological capability, supervision and enforcement, waste management policy, and compliance from the corporate companies [10][11].

Waste management has been a long-standing issue in Malaysia [12][13]. One of the main challenges in waste management is managing the scheduled waste that involves collection, transportation, treatments, and disposal of the scheduled waste [14]. The Environmental Quality (Scheduled Wastes) Regulations 2005 (amendment 1989) defined scheduled wastes as any waste falling within the categories of waste listed in the First Schedule, which includes 77 scheduled waste code categories [15]. Some categories of waste in the Schedule are classified as hazardous waste due to their toxicity and hazardous characteristics [16]. Since 1995, Kualiti Alam Sdn Bhd, a privately owned company, has been given exclusive rights and responsibilities to integrate the collection, treatments, and disposal of scheduled waste in Malaysia [17]. Despite having regulations and establishment of the hazardous waste management policies, the event of illegal dumping of hazardous waste has occurred sporadically in the country [18][19].

The Department of Environment (DOE) under The Ministry of Environmental and Water is the responsible agency to ensure the industry’s compliance with the environmental protection rules and regulations. However, several obstacles present challenges to the implementation of scheduled waste regulations. A study by Khoo et al. [20] found that manufacturing industries in the state of Malacca generally had poor compliance to all the three occupational and environmental health-related laws in Malaysia, which are the Occupational Safety and Health Act (OSHA) 1994, Environmental Quality Act 1974 (Act 127) and Guided Self-Regulation Environmental Mainstream Tools (EMT). In 2004, metal hydroxide sludge from Taiwan was illegally imported and stored at Simpang Renggam, Johor [21]. Another similar incident was in Segamat, Johor that caused the evacuation of 300 villagers from their homes after 300 tons of toxic waste was buried at an illegal dumpsite, emitting ammonia fumes [22]. In 2019, Malaysia was shocked by an incident of chemical poisoning in Pasir Gudang that caused thousands of people to feel sick after being exposed to a mixture of chemicals illegally dumped into the Kim Kim River, Pasir Gudang, Malaysia [23][24][25][26]. Although there are many studies involving incidents of illegal waste disposal that have been documented [18][19][20][25][26], to date, no studies have examined the health impact of improper disposal of hazardous waste on children in Malaysia.

The objective of this study is to identify and estimate the potential health risks to children associated with poor hazardous waste management based on a case study in Pasir Gudang, Malaysia. Health risk assessment of a chemical incident on children is generally conducted by evaluation and quantification of contaminants for children [27][28][29]. However, this approach is not always possible in a real crisis or disaster [30]. Hence, this study introduced a risk assessment based on a real case scenario relating to environmental contamination of chemical compounds and the analysis of its possible health-related effects to children. The findings will serve as an important reference to researchers and policy makers in improving policies on environmental protection and public health.

2. Study Area

Malaysia is experiencing a rapid economy development and continuous improvement in living standards. Malaysia’s economy is the most competitive economy among the developing countries in Asia. It ranked 25th out of 140 economies in the global index [31]. The growth of the economy and population is posing a burden on the environment due to greenhouse gases emission, environmental degradation, and waste generation, just to name a few. According to the UN environment report [32], Malaysia generated about 1,600,000 tons of all classes of hazardous waste per year, the third among Association Of Southeast Asian Nations (ASEAN) countries behind Thailand and Philippines, which generated about 3,300,000 and 1,700,000 tons per year, respectively. The manufacturing sector in Malaysia is the leading sector generating toxic and hazardous waste [33]. As waste generation is expected to rise with the population growth and economic development, Malaysia is likely to experience an increase in hazardous waste generation.

Pasir Gudang is a significant industrial and port city in Malaysia [34]. It is located at the southwestern part of Johor Bahru district, Johor, Malaysia (Figure 1). Established in 1918, Pasir Gudang was formerly a fishing village that was then transformed into a rubber estate during the British rule in Malaya. Subsequently, the area was further developed by the Johor State Government into residential and industrial areas [35]. In the present day, Pasir Gudang has developed into a port and industrial town. The main economic activities include transportation and logistics, palm oil storage, manufacturing of electronic goods, and other heavy industries such as petrochemicals and shipbuilding [36][37][38]. It has two ports, namely Johor Port and Tanjung Langsat Port, which are among the busiest ports in Malaysia.

Ijerph 18 02221 g001 550

Figure 1.

Location of Pasir Gudang.

Residents of Pasir Gudang are prone to environmental pollution due to its rapid development and industrialization. Prior to the incident of illegal toxic waste in 2019, the environment in Pasir Gudang specifically and areas around the Johor Straits in general were exposed to pollutants resulting from anthropogenic activities [26][39]. The 15 km-long Kim Kim River, running from the Masai sub-district and flowing southward in Pasir Gudang into the Straits of Johor, is considered one of the most polluted rivers in Johor Bahru [40][41]. Keshavarzifard et al. [40] discovered a high level concentration of total polycyclic aromatic hydrocarbons (PAHs) on the surface of the Kim Kim River, which may increase the risk of developing cancer.

34. Respiratory Diseases

This study found that most of the children who were taken to hospitals were due to shortness of breath. Studies on environmental exposure largely found a relationship with respiratory symptoms and complications [42][43]. Exposure to benzene has been associated with increased risk of respiratory symptoms in children including wheezing and shortness of breath [44]. Children exposed to 1 μg/m3 higher levels of benzene and formaldehyde had a higher odds ratio (OR) of having rhinitis (OR 1.03, 95% confidence interval (CI) 1.01–1.06), exacerbation of bronchial asthma (OR 1.05, 95% CI 1.01–1.10) and dry cough (OR 1.05, 95% CI 1.01–1.10) [42]. Epidemiological studies on the long-term effects due to inhalation of acrolein and acrylamide have not been identified. However, animal and in vitro human airway tissue model studies showing exposure to acrolein and acrylamide were linked to oxidative stress [45][46][47] and inflammation response [48], which led to increased mucus secretions, edema of the bronchial wall, bronchoconstriction, and tissue damage [49]. Hence, this chemical reaction indicated the possibility of children suffering from respiratory symptoms due to exposure to high concentrations of toxic chemicals from the illegal waste dumping site in the Kim Kim River incident.

In terms of the magnitude of disaster, the Pasir Gudang chemical incident was less severe in comparison to the infamous Bhopal disaster that occurred in 1984, whereby 40 tons of methyl isocyanate gas was released following an industrial-related accident [50]. While no human casualties were reported in Pasir Gudang, the Bhopal disaster had resulted in a loss of 10,000 lives within a few days of the occurrence [51]. Another example of a chemical incident that affected respiratory health occurred in 2013 when an ammonia leak incident was reported from a chemical plant located in Rouen, northwest France [52][53]. This chemical leak recorded no fatalities; however, the released chemical had wafted across the English Channel into England, resulting in a transboundary pollution in England. In the situation of the Pasir Gudang incident, there was no transboundary chemical pollution reported.

45. Cancer

From the result of this study, the risk of developing cancer resulting from the exposure of chemical agents in the Kim-Kim River incident needs further investigation. However, a few studies have investigated the relationship between exposure to benzene and other volatile organic compounds (VOCs) [54][55]. Benzene exposure during childhood was associated with acute lymphocytic leukemia and acute myeloid leukemia of relative risk (RR) 1.0 (95% CI: 0.6–1.7) and RR 1.9 (95% CI: 0.3–11.1) [55]. In general, VOCs can be found around the Pasir Gudang area due to industrial activities such as ship washing activities, and petrochemical and plastic production [56]. As such, poor management of industrial hazardous waste may result in an increase in the risk of developing cancer to the surrounding population.

56. Mental Health

Exposure to traumatic events either, experiencing or witnessing a harmful situation, poses a threat to an individual’s or population’s mental health. Such events may include, among others, natural disaster, motor vehicle accident, physical injury, and exposure to hazardous material. Approximately 10% of children who were exposed to such events will develop post-traumatic stress disorder (PTSD) [57]. Children with PTSD may experience intrusive memories, avoidance, negative changes in thinking and mood, and changes in physical and emotional reactions. Even though children are generally exposed to the same spectrum of stressors with adults, they are more vulnerable because their emotions and cognition are still immature, they have limited life experience and they lack in coping strategies. Although PTSD was not reported among children following the events in Pasir Gudang, they are at risk of developing PTSD as the onset may develop between 3–12 months post-traumatic event [58].

67. Limitations

There are several limitations in this study that need to be highlighted. First, this study did not obtain the victims’ biological markers and level of ambient air chemical concentration, due to data confidentiality. Hence, the findings from this research must be interpreted cautiously. Secondly, this study included only children (6–17 years old) from the five affected schools. In reality, there were more children exposed to the hazardous chemical, but due to limitations, it was not possible to measure the whole population of children affected. Therefore, caution should be taken with generalizing the findings to the wider population. Finally, this study only assessed limited numbers of hazardous chemicals involved in the incident. Future research should consider including substantial environmental emissions associated with respiratory diseases among children. The incident in Pasir Gudang may be aggravated by the industrial activities in the area that have now reached saturation level [59].

78. Policy Implication

The pollution in Pasir Gudang is an example of the failure to learn from past incidents that had occurred in Johor specifically and other places in the country in general [18][19][21][22]. Past experience on similar incidences should be translated into preventive measures as scientific evidence has shown that pollution incidents in the Straits of Johor and Johor’s rivers had been documented and is a repeated occurrence [60][61][62][63][64]. That scientific evidence is important and should be utilized by the relevant enforcement agencies in their effort to improve the quality of services and preventive measures. While the findings of this review may be inconclusive, it indicates that preventive measures are necessary to protect the public’s health from the outcome of an improper hazardous waste disposal. Therefore, this study suggests several recommendations to be considered for future environmental and public health policy makers. First, the health risk assessment framework may be used to identify risks and possible health impacts related to environmental issues. Findings of the health risk assessment may guide policy makers in making environmental policies to improve the situation in the country. Secondly, public health officers should implement the health risk assessment in high-risk areas such as Pasir Gudang to identify vulnerable populations for public health risk management and risk mitigation strategies. Thirdly, all parties should comply with existing environmental laws and regulations, such as the Environmental Quality Act 1974 (Act 127) [65]. Hazardous waste must be disposed of in designated facilities and should not be discarded into the environment such as rivers and landfills. Finally, collaboration between universities, industries and policy makers should be nurtured with the aim of discovering sustainable solutions to complex environmental, health, social, and economic challenges.

References

  1. Duan, H.; Huang, Q.; Wang, Q.; Zhou, B.; Li, J. Hazardous waste generation and management in China: A review. J. Hazard. Mater. 2008, 158, 221–227.
  2. Haq, I.; Chakrabarti, S.P. Hazardous waste management in developing countries (India): A case study. Int. J. Environ. Stud. 1997, 53, 215–234.
  3. Ferronato, N.; Torretta, V. Waste Mismanagement in Developing Countries: A Review of Global Issues. Int. J. Environ. Res. Public Health 2019, 16, 1060.
  4. El-Fadel, M.; Zeinati, M.; El-Jisr, K.; Jamali, D. Industrial-waste management in developing countries: The case of Lebanon. J. Environ. Manag. 2001, 61, 281–300.
  5. Anandalingam, G.; Westfall, M. Hazardous Waste Generation and Disposal: Options for Developing Countries. Nat. Resour. Forum 1987, 11, 37–47.
  6. Begum, R.A.; Siwar, C.; Pereira, J.J.; Jaafar, A.H. Implementation of waste management and minimisation in the construction industry of Malaysia. Resour. Conserv. Recycl. 2007, 51, 190–202.
  7. Ziraba, A.K.; Haregu, T.N.; Mberu, B. A review and framework for understanding the potential impact of poor solid waste management on health in developing countries. Arch. Public Health 2016, 74, 1–11.
  8. Nnorom, I.; Osibanjo, O. Overview of electronic waste (e-waste) management practices and legislations, and their poor applications in the developing countries. Resour. Conserv. Recycl. 2008, 52, 843–858.
  9. Fazzo, L.; Minichilli, F.; Santoro, M.; Ceccarini, A.; Della Seta, M.; Bianchi, F.; Comba, P.; Martuzzi, M. Hazardous waste and health impact: A systematic review of the scientific literature. Environ. Health 2017, 16, 1–11.
  10. Karthikeyan, L.; Suresh, V.M.; Krishnan, V.; Tudor, T.; Varshini, V. The Management of Hazardous Solid Waste in India: An Overview. Environments 2018, 5, 103.
  11. Li, M.; Xu, J.; Li, B. Analysis of Development of Hazardous Waste Disposal Technology in China. In Proceedings of the IOP Conference Series: Earth and Environmental Science; IOP Publishing: Bristol, UK, 2018; Volume 178, p. 012027.
  12. Ikau, R.; Joseph, C.; Tawie, R. Factors Influencing Waste Generation in the Construction Industry in Malaysia. Procedia-Soc. Behav. Sci. 2016, 234, 11–18.
  13. Sari, N.M.; Bin Mokhtar, M. Hazardous Waste Management in Malaysia: The Needs of Environmental Forensic. In From Sources to Solution; Springer International Publishing: Berlin, Germnay, 2013; pp. 61–66.
  14. Ishak, M.B. The Law of Industrial Waste Management in Malaysia. Available online: (accessed on 16 February 2021).
  15. Federal Subsidiary Legislation. Environmental Quality (Scheduled Wastes) Regulations 2005, PU(A) 294/2005. In Environmental Quality Act 1974(Act 127); International Law Book Services: Petaling Jaya, Malaysia, 2019.
  16. Noor Artika, H.; Yusof, M.Z.; Nor Faiza, M.T. An Overview of Scheduled Wastes Management in Malaysia. J. Wastes Biomass-Manag. 2019, 1, 1–4.
  17. Alam, K. Scheduled Waste Management. Available online: (accessed on 17 February 2021).
  18. Rashid, Z.A.; Alias, A.B.; Aris, M.J.; El Harbawi, M.; Rahman, N.A.; Som, A.M. Hazardous waste management: Current status and future strategies in Malaysia. Int. J. Environ. Eng. 2010, 2, 139–158.
  19. Zainun, N.Y.; Rahman, I.A.; Rothman, R.A. Mapping of Construction Waste Illegal Dumping Using Geographical Information System (GIS). In Proceedings of the IOP Conference Series: Materials Science and Engineering; IOP Publishing: Bristol, UK, 2016; Volume 160, p. 012049.
  20. Khoo, N.K.; Hussin, H.; Abdullah, N. Occupational Safety and Health (O.S.H) Towards Green Environment Practices at Malaysia Small and Medium Manufacturing Sector; Science Publishing Corporation: Ras Al-Khaimah, United Arab Emirates, 2019; Volume 8.
  21. Johor Firm Used Fake Papers to Import Sludge. Available online: (accessed on 12 April 2020).
  22. Tan, M.; Sim, L.L. 300 Tonnes of Toxic Waste Emitting Ammonia Fumes. Available online: (accessed on 12 April 2020).
  23. Haidar, R.T.; Ibrahim, M.F.; Mohd Aris, N.; Selvaraji, L.; Rusli, N. The Use of “WISER” Smartphone Application in Aiding a Chemical Disaster Management: Sungai Kim Kim Experience. Available online: (accessed on 29 January 2021).
  24. Salvaraji, L.; Toha, H.R.; Mohd Aris, N.; Ayob, Q.A.; Nordin, A.; Abdul Latif, N.; Rosli, L.; Mahjom, M.; Kassim, N.; Che Mat Din, S.N.A.; et al. Application of Occupational Health Surveillance Program among Responder’s during Chemical Incident at Pasir Gudang, Johor. Available online: (accessed on 29 January 2021).
  25. Chinnayah, T.; Abdul Aziz, S.; Che Mat Din, S.N.; Mahdan, N.B.; Rosli, N.; Ibrahim, M.F.; Khida, N.; Othman, N.E.; Harun, R.; Ahmad, S. Largest Acute Chemical Incident in Malaysia, March 2019: Opportunity to Assess the Preparedness and Re-sponse Capacity. Available online: (accessed on 25 November 2020).
  26. Yap, C.K.; Peng, S.H.T.; Leow, C.S. Contamination in Pasir Gudang Area, Peninsular Malaysia: What can we learn from Kim Kim River chemical waste contamination? J. Humanit. Educ. Dev. 2019, 1, 82–87.
  27. Arnold, S.M.; Angerer, J.; Boogaard, P.J.; Hughes, M.F.; O’Lone, R.B.; Robison, S.H.; Schnatter, A.R. The use of biomonitoring data in exposure and human health risk assessment: Benzene case study. Crit. Rev. Toxicol. 2013, 43, 119–153.
  28. Black, J.C.; Welday, J.N.; Buckley, B.; Ferguson, A.; Gurian, P.L.; Mena, K.D.; Yang, I.; McCandlish, E.; Solo-Gabriele, H.M. Risk Assessment for Children Exposed to Beach Sands Impacted by Oil Spill Chemicals. Int. J. Environ. Res. Public Health 2016, 13, 853.
  29. Morakinyo, O.M.; Mokgobu, M.I.; Mukhola, M.S.; Engelbrecht, J.C. Health risk assessment of exposure to ambient concentrations of benzene, toluene and xylene in Pretoria West, South Africa. Afr. J. Sci. Technol. Innov. Dev. 2017, 9, 489–496.
  30. Wood, M.H.; Fabbri, L. Challenges and opportunities for assessing global progress in reducing chemical accident risks. Prog. Disaster Sci. 2019, 4, 100044.
  31. Schwab, K. The Global Competitiveness Report 2019. Available online: (accessed on 10 April 2020).
  32. Jain, A.; Borongan, G.; Kashyap, P.; Thawn, N.S.; Honda, S.; Memon, M. Summary Report: Waste Management in ASEAN Countries. Available online: (accessed on 10 April 2020).
  33. Aja, O.C.; Al-Kayiem, H.H.; Zewge, M.G.; Joo, M.G.Z.A.M.S. Overview of Hazardous Waste Management Status in Malaysia. In Management of Hazardous Wastes; IntechOpen: London, UK, 2016.
  34. Abdullah, J.; Ahmad, Z.; Shah, R.N.H.R.A.; Anor, N. Port City Development and Quality of Life in Pasir Gudang Port, Johor, Malaysia. Procedia -Soc. Behav. Sci. 2012, 35, 556–563.
  35. MPPG. Official Portal of Pasir Gudang Municipal Council (MPPG). Available online: (accessed on 11 April 2020).
  36. Teh, B.T.; Ho, C.S.; Matsuoka, Y.; Chau, L.W.; Gomi, K. Determinant factors of industrial symbiosis: Greening Pasir Gudang industrial park. In Proceedings of the IOP Conference Series: Earth and Environmental Science; IOP Publishing: Bristol, UK, 2014; Volume 18, p. 12162.
  37. Emran, N.; Zaki, B. Impact of Service Quality of Land Transportation on Customer Satisfaction at Johor Port Logistics. J. Public Value Adm. Insights 2018, 1, 7–13.
  38. Sarmldi, M.R.; Hussain, M.A.; Ramli, W.; Daud, W. Overview Petrochemical Based Industries in Malaysia. ASEAN J. Chem. Eng. 2001, 1, 7–16.
  39. Koh, H.-L.; Lim, P.-E.; Midun, Z. Management and control of pollution in Inner Johore Strait. Environ. Monit. Assess. 1991, 19, 349–359.
  40. Keshavarzifard, M.; Zakaria, M.P.; Keshavarzifard, S.; Sharifi, R. Distributions, Composition Patterns, Sources and Potential Toxicity of Polycyclic Aromatic Hydrocarbons (PAHs) Pollution in Surface Sediments from the Kim Kim River and Segget River, Peninsula Malaysia. Available online: (accessed on 11 April 2020).
  41. Alkhadher, S.A.A.; Zakaria, M.P.; Yusoff, F.M.; Kannan, N.; Suratman, S.; Magam, S.M.; Masood, N.; Keshavarzifard, M.; Vaezzadeh, V.; Sani, M.S.A. Distribution and sources of linear alkyl benzenes (LABs) in surface sediments from Johor Bahru Coast and the Kim Kim River, Malaysia. Environ. Forensics 2016, 17, 36–47.
  42. Idavain, J.; Julge, K.; Rebane, T.; Lang, A.; Orru, H. Respiratory symptoms, asthma and levels of fractional exhaled nitric oxide in schoolchildren in the industrial areas of Estonia. Sci. Total. Environ. 2019, 650, 65–72.
  43. Cipolla, M.; Bruzzone, M.; Stagnaro, E.; Ceppi, M.; Izzotti, A.; Culotta, C.; Piccardo, M.T. Health Issues of Primary School Students Residing in Proximity of an Oil Terminal with Environmental Exposure to Volatile Organic Compounds. BioMed Res. Int. 2016, 2016, 1–10.
  44. D’Andrea, M.A.; Reddy, G.K. Health Risks Associated with Benzene Exposure in Children: A Systematic Review. Glob. Pediatr. Health 2018, 5, 2333794x18789275.
  45. Pan, X.; Wu, X.; Yan, D.; Peng, C.; Rao, C.; Yan, H. Acrylamide-induced oxidative stress and inflammatory response are alleviated by N-acetylcysteine in PC12 cells: Involvement of the crosstalk between Nrf2 and NF-κB pathways regulated by MAPKs. Toxicol. Lett. 2018, 288, 55–64.
  46. Yilmaz, B.O.; Yildizbayrak, N.; Aydin, Y.; Erkan, M. Evidence of acrylamide- and glycidamide-induced oxidative stress and apoptosis in Leydig and Sertoli cells. Hum. Exp. Toxicol. 2017, 36, 1225–1235.
  47. Snow, S.J.; McGee, M.A.; Henriquez, A.; Richards, J.E.; Schladweiler, M.C.; Ledbetter, A.D.; Kodavanti, U.P. Respiratory Effects and Systemic Stress Response Following Acute Acrolein Inhalation in Rats. Toxicol. Sci. 2017, 158, 454–464.
  48. Xiong, R.; Wu, Q.; Muskhelishvili, L.; Davis, K.; Shemansky, J.M.; Bryant, M.; Rosenfeldt, H.; Healy, S.M.; Cao, X. Evaluating Mode of Action of Acrolein Toxicity in an In Vitro Human Airway Tissue Model. Toxicol. Sci. 2018, 166, 451–464.
  49. Santus, P.; Corsico, A.; Solidoro, P.; Braido, F.; Di Marco, F.; Scichilone, N. Oxidative Stress and Respiratory System: Pharmacological and Clinical Reappraisal of N-Acetylcysteine. COPD: J. Chronic Obstr. Pulm. Dis. 2014, 11, 705–717.
  50. Broughton, E. The Bhopal disaster and its aftermath: A review. Environ. Health 2005, 4, 1–6.
  51. Ipe, M. Bhopal Gas Tragedy: Lessons for corporate social responsibility. Soc. Responsib. J. 2005, 1, 122–141.
  52. Negre, E. Crisis management and distrust: Study of an industrial accident in France. In Proceedings of the 54th Hawaii International Conference on System Sciences, Maui, HI, USA, 5–8 January 2021; p. 2235.
  53. Dakkoune, A.; Vernières-Hassimi, L.; Leveneur, S.; Lefebvre, D.; Estel, L. Analysis of thermal runaway events in French chemical industry. J. Loss Prev. Process. Ind. 2019, 62, 103938.
  54. Sakizadeh, M. Spatiotemporal variations and characterization of the chronic cancer risk associated with benzene exposure. Ecotoxicol. Environ. Saf. 2019, 182, 109387.
  55. Raaschou-Nielsen, O.; Hvidtfeldt, U.A.; Roswall, N.; Hertel, O.; Poulsen, A.H.; Sørensen, M. Ambient benzene at the residence and risk for subtypes of childhood leukemia, lymphoma and CNS tumor. Int. J. Cancer 2018, 143, 1367–1373.
  56. Montero-Montoya, R.; López-Vargas, R.; Arellano-Aguilar, O. Volatile Organic Compounds in Air: Sources, Distribution, Exposure and Associated Illnesses in Children. Ann. Glob. Health 2018, 84, 225–238.
  57. Charnsil, C.; Narkpongphun, A.; Chailangkarn, K. Post-traumatic stress disorder and related factors in students whose school burned down: Cohort study. Asian J. Psychiatry 2020, 51, 102004.
  58. Carty, J.; O’Donnell, M.L.; Creamer, M. Delayed-onset PTSD: A prospective study of injury survivors. J. Affect. Disord. 2006, 90, 257–261.
  59. Noh, M.F.; Malek, R. Pakar Belum Temui Bukti Sisa Toksik Bawah Tanah. Available online: (accessed on 20 November 2020).
  60. Zulkifli, S.Z.; Ismail, A.; Mohamat-Yusuff, F.; Arai, T.; Miyazaki, N. Johor Strait as a Hotspot for Trace Elements Contamination in Peninsular Malaysia. Bull. Environ. Contam. Toxicol. 2010, 84, 568–573.
  61. Yap, C.K.; Ismail, A.; Tan, S.G. The Impact of Anthropogenic Activities on Heavy Metal (Cd, Cu, Ph and Zn) Pollution: Comparison of the Metal Levels in the Green-Lipped Mussel Perna viridis (Linnaeus) and in the Sediment from a High Activity Site at Kg. Pasir Puteh and a Relatively Low A. Available online: (accessed on 12 April 2020).
  62. Yap, C.K.; Ismail, A.; Edward, F.B.; Tan, S.G.; Siraj, S.S. Use of different soft tissues ofPerna viridis as biomonitors of bioavailability and contamination by heavy metals (Cd, Cu, Fe, Pb, Ni, and Zn) in a semi-enclosed intertidal water, the Johore Straits. Toxicol. Environ. Chem. 2006, 88, 683–695.
  63. Yap, C.K.; Edward, F.B.; Tan, S.G. Heavy Metal Concentrations (Cu, Pb, Ni and Zn) in the Surface Sediments from a Semi-Enclosed Intertidal Water, the Johore Straits: Monitoring Data for Future Reference. J. Sustain. Sci. Manag. 2010, 5, 44–57.
  64. Maadin, F.S.; Abdul Rahman, M.; Abdul Zawawi, M.; Azman, S.; Oladokun, S. Copper and Zinc Accumalation in Sediment at Straits of Johor. Malays. J. Civ. Eng. 2016, 314–322.
  65. The Commissiner of Law Revision, M. Laws of Malaysia Environmental Quality Act 1974. Available online: (accessed on 10 April 2020).
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
ScholarVision Creations
Feedback