Prevalence, causes and impacts of human trafficking in Asian countries: A scoping review [version 1; peer review: 1 approved, 1 approved with reservations, 1 not approved]

Background: In Asian countries, human trafficking is often encountered as forced labor, forced marriage, sex trafficking, men, women, and children exploitation. This review points out how human trafficking activities are prevalent in Asian countries and also reveals different causes that are the basis of increasingly human trafficking in Asian countries such as poverty, unemployment, political uncertainty, war, natural disaster, corruption and weak policies. Human trafficking also creates huge health, physical, psychological and social implications on individuals and the overall society. Methods: The purpose of this study is to collect evidence on human trafficking in Asian countries. A scoping review methodology was used to systematically search online databases including Sage Journals Online, Wiley Online, Hein Online, Taylor & Francis Online, Web of Science, and Scopus literature to amalgamate information on this issue. For the purposes of this article, 64 studies met the inclusion criteria after searching and screening a total number of 1,278 studies. Results: The findings of


Introduction
Human trafficking is one of the hugely intensifying and alarming illicit worldwide trades. It is a process where human victims have been moved either voluntarily or involuntarily i.e., kidnapping, abduction, deception, use of force, fraudulent recruitment or giving and receiving payments to maintain the hegemonic power over others by the traffickers within the nation or across borders for various exploitation purposes. 1 Furthermore, exploitation is also meant to include, inter alia prostitution of other persons, or other forms of sexual transgression, forced labour or services, slavery, or practices akin to slavery, servitude, or removal of human organs. In essence, it is apposite to say that human trafficking is a heinous, alarming cross border crime and a bane to humanity as it violates and transgress upon the basic human rights and personal liberties due to its lucrative and rapacious illegal business demand across the globe. There is no doubt that human trafficking is a modern-day form of slavery. The practice of abducting and tricking innocent people for the purpose of money exploitation and servitude is horrific and vile enough to infringe on human rights. 2,3 While the effects of human trafficking are diverse, ranging from public health to environmental issues, the spectrum of violence has the biggest impact on the victims. 4 In regard to public health, the problems that lie as a result of this crime include both physical and behavioral disturbances, such as the consequences of physical and sexual abuse. 5 Living in crowded and cramped conditions often results in the spread of viruses and lethal diseases such as tuberculosis and infectious diarrhea. 2 Not only that, sexually transmitted infections are more pronounced in cases where sexual activities are involved. 6 Among the victims, there is a high prevalence of mental health issues such as anxiety, depression, trauma, and phobias as a result of physical and emotional abuse. 4 Concerning environmental issues, most industries involved in human trafficking are likely to have a negative impact on the environment, which eventually leads to climate change. 7 The increase in the number of migrant workers in forced labour activities has been proven as a major contributor to environmental damage. 8 The demand for more workers in industries that heavily depend on human labour such as agriculture, fishing, logging, and mining, has increased the exploitation of both people and natural resources. 9 Hence, the need to acknowledge that human trafficking can cause many detrimental issues must be taken seriously by many in order to end this crime.
There are millions of people including men, women and children around the world that are trafficked within the country or across the borders for different purposes i.e., forced labor, sexual exploitation and forced marriages. 10 Around 800,000 women cross international borders for sexual exploitation, where 54% send to Central Asia and Europe, 25% to Southeast Asia, 14% to Middle East and Africa and 7% to America. Global Survey Index 2016, noted that nearly 45.8 million victims of human trafficking in 167 countries around the globe. 11 It is also reported, that human trafficking has been considered one of the most remunerative methodical crimes, with illegal profit exceeding 150 billion US dollars every year and Asian region recorded the highest profit of 51.8 billion US dollars per year. 12,13 Because of these illicit profits, large number of trafficked women, men and children victims had their freedom and basic fundamental human rights subjugated from them. 13 It is estimated that every year around 5.5 million children are forced into labor conditions and 1.2 million are trafficked victims. 14 However, boys and transgender persons are also trafficked. 15 In general, human trafficking is an organized syndicated crime that is considered to be the third-largest illegitimate profiting crime in the world after drugs and weapons. 16 Asian countries are the main fertile centers of human trafficking such as Pakistan, India, Bangladesh, Afghanistan, China, Malaysia, Sri Lanka, Philippine, Nepal, Thailand, Myanmar. 17 It is to be noted that every year, millions of people become victims of human trafficking in Asian countries. 11,17 Asia is considered as a largest continent of the world with a size of about 44 million km 2 and with having large number of 4.6 billion population. 18 With the inferential movement of people and expansion of population, the natural geography of Asia has widely changed. Because of such geographical and demographic changes, majority of people in Asian countries are facing huge social, economic and political difficulties. 19 Apart from that, with the eruption of globalization, with preamble borders and with easy visa requirements, it is very easy for the migrant population to enter into majority of the Asian countries. Through this process, human trafficking and other criminal activities increase tremendously. 20 Studies in Malaysia show that it is important to identify the nature of crimes in order to formulate preventive efforts. [21][22][23][24][25][26][27][28] The goal of this review is to mainstream the activities of human trafficking in Asia alongside the violation of national and international human rights. Additionally, this review attempts to tap deeper into the nature of crime and to highlight the incidents of human trafficking in Asia and recommend suggestions to policymakers and practitioners to prioritize the concerned issue based on the findings of this review. The objectives of this review were as follows: 1. To identify the prevalence of human trafficking in Asian countries.
2. To assess the root causes and impacts of human trafficking in Asian countries.
3. To analyse the research gap in the literature of human trafficking in Asian countries.

Methods
One of the prominent features of the scoping review is to widely use all related literature according to the study design. In this review, the preferred reporting items for systematic reviews and meta-analysis protocols (PRISMA-P) and PRISMA extension for scoping review checklist were used as a guideline. 29,30 Consequently, this study consists of empirical, conceptual, and theoretical literature regarding human trafficking. Following are the details of the methods.

Search strategy
For the purpose of this review, the author only relied upon electronic databases to collect relevant research data. The specific databases that were used for searching the articles include, Sage Journal Online, Wiley Online, Hein Online, Taylor & Francis Online, Web of Science, and Scopus literature. These databases have rich data including, scholarly articles, journals, reports and other scholarly data that can be easily explored for a scoping review. The search for data took place from January 2015 to June 2022, by using different terms and keywords. The search strategy was as follows; (Human trafficking in Asia, social and economic factors contributing to human trafficking, causes and impacts of human trafficking, and names of Asian countries).

Eligibility criteria
Various types of studies, reviews, and international professional reports included in the English language that meet the inclusion criteria, addressed the research objectives, full-text articles, and focused on human trafficking are presented in this review. Likewise, studies or reports published before January 2015, did not have a link with human trafficking and illegal migration, and did not focus on Asian countries were excluded from this review.

Screening and selection process
For this review, 1,278 sources were found in the online electronic databases. Initially, every article went through the process of screening; based on the title and abstract. Articles unrelated to human trafficking activities and irrelevant to Asian countries, were published before January 2015 and duplicates were removed in the process. After removing these data, a total number of 147 articles were selected for in-depth screening. Next, 83 articles and reports were removed at the eligibility stage because their content and concept did not match and be in tandem with the objectives of the study. Finally, 64 articles were selected and reviewed for this research. Figure 1 describes the flowchart of the scoping review process and identification and Table 1 summarizes the reviewed studies.

Result
Selection and characteristics of sources of evidence The scoping review selection process and summary of quality assessment for all reviewed literature are presented in Figure 1 and Table 1. More specifically, the search strategy for this review was limited to Asian countries, a total number of 64 articles were included in this review and the content of reviewed articles reflated the prevalence of human trafficking, causes of human trafficking and impacts of human trafficking in Asian countries. For the effects and results of the individual sources, the following are the variables obtained by the researchers from the selected articles.

Prevalence of human trafficking in Asia
In the 21 st century, international political environment pose different major issues of concern. The most passing issues is the prevalence of trafficking in persons across the globe. The history of human trafficking could be traced back many years ago when slavery and forced servitude were among the said issues. We might think that in the 21 st  Likewise, women and children are also trafficked to Pakistan and other Asian countries for forced marriage and forced labor purposes. 36 In the last 30 years, more than 30 million of children and women are sexually victimized in Asia. Mostly Asian trafficking victims are sent to Asian countries, i.e., Thailand, Japan, Pakistan, India, Bangladesh, Nepal and Taiwan. 37 The latest global survey index indicates that 35.8 million people are suffering due to enslavement. These estimations based on different existing studies and on face to face-to-face interviews conducted by Gallop  Likewise, a report on human rights indicated that in Bangladesh, 10,000 to 20,000 women and men are trafficked internally as well as on international borders to India, Pakistan, Bahrain, Kuwait and many other Asian countries for sexual exploitations. 39 Similarly, in India 14 million of human trafficking cases estimated in year 2014, which includes victims of labor trafficking, sex trafficking and forced marriages. 40 In year 2016, Global Slavery Index indicated that majority of 58% of human trafficking victims are reported in Asian countries specifically in China, India, Pakistan, Uzbekistan and Bangladesh. 11 It is noted that 57% of workers (women and children) are the victims of human trafficking in Thailand. Generally, Thailand also transports human trafficking victims to other countries such as India, Malaysia, Japan, Hong Kong, Germany and Australia for the purpose of sex business. 41 Likewise, majority of North Korean women trafficked to Asian countries for sexual exploitations, are being sold to Chinese men especially. 42 Malaysia is also one of the targeted countries for the human trafficking activities in Southeast Asia due to its impressive economic growth, strategic location and political stability. 43 It is of irresistible truth that on yearly basis, Malaysia has a large influx of migrant workers, be it documented or undocumented working in various fields of economy and being susceptible to human trafficking thereafter.

Causes of human trafficking in Asia
Human trafficking is considered a fast-growing crime in the world. It is imperative to know why an individual becomes a victim of trafficking through the use of deception and coercion. The causes of human trafficking vary from region to region and country to country. In Asian countries, many push and pull factors contribute and describe the root causes of human trafficking. In the general contexts, it can be divided into four main categories namely political, economic, environmental and cultural. 44 There are several causes as to the occurrence of human trafficking. In this study, the author will focus on some major causes which significantly and prevalently contribute towards human trafficking. These causes are the following: Poverty and unemployment: Poverty is one of the major causes that contribute to human trafficking. 2 It is the reason behind the decision of an individual to become a prostitute or forced labor. It is primarily because of their weak economic duress and fiscal status. The gap between developing and developed countries with poverty and marginalization has fabricated with globalization. Majority of population in Asian countries live in third world conditions with less basic infrastructure and employment opportunities. Traffickers take advantage from these conditions and give false offers to poor people to exploit them. 36,38,45 Many individuals leave their families and home because of the financial, educational and job opportunities, but most of them were coerced into trafficking. 16 A study indicates, that every year five to seven thousands girls are trafficked to India from Nepal. These girls are sold by the poor parents on the façade of bogus marriages or employment promises. A qualitative study resulted that because of economic troubles, Thai and Filipina women had been trafficked as a sex worker. 46 Likewise, many Pakistani and Indian women, men and children migrated to Europe, America and other Asian developed countries for the purpose of low skilled jobs like constrictions and driving. Many of them become the victims of human trafficking. 10,12,44 In addition, recently more than 130 Bangladeshis were trafficked to Thailand with fake promises for employment. It is also noted that 200,000 Filipinos became the victims of labor trafficking. 47 Large number of people from central Asian countries i.e., Kyrgyzstan and Uzbekistan are trafficked on the promises of better socio-economic conditions and bright future. In addition, 70% of North Korean women are trafficked to China for the purpose of forced marriage and forced labor. 47,48 Similarly, because of fraudulent employment offers, many men and women are trafficked from Sri Lanka, Bhutan, Maldives and Afghanistan. 39 Environmental and manmade disaster: In today's world, many populations migrated from one place to another place because of a conflict, natural calamity, terrorism and war. The issue of human trafficking burns whenever a disaster strikes. 49 The United Nations (UN) environmental program has stated that because of disasters 20% to 30% of human trafficking activities increased. 50 It is reported that by the end of 2017, 68.5 million people were forcibly displaced due to conflict and natural disasters. More than two-thirds of them originated from Afghanistan, South Sudan, Somalia, Syria and Myanmar in the form of refuges, IDPs and asylum seekers. 51 Similarly, due to militancy and terror, large numbers of Rohingya Muslims trafficked to Bangladesh, Malaysia, Indonesia and other countries of Asia. A number of victims were sexually abused, raped, put to labor by force and killed. Same cases were also noted in Iraq and Libya. 52 Furthermore, climate changes and other forms of environmental changes also lead to child labor, domestic abuse and human trafficking. 50 During flood in year-2011, approximately 13 million people were affected in Thailand. The consequences of this natural disaster were encountered as economic inequality, political and most importantly human rights violation and human trafficking. 53 Likewise, during 2010-flood, the cases of rapes, sexual harassment and trafficking of young girls and women increase in Pakistan and Bangladesh. Same scenario was also reported after 2005 earthquake in Kashmir, Pakistan. 54 In addition, after the 2015 earthquake in Nepal, traffickers targeted mostly children in camps and shelters for victimization. 50 Weak policies and corruption: In the 21 st century the political model of the world changed because of war and political unrest in the Middle East. Majority of traffickers take advantage from these favourable environments. 55 Corruption is the main compound of weak policies and law enforcement. 56 The irregular migration increases because of the high level corruption and weak policies by the government and political leaders. 57 For example, the border of India and Nepal monitored on regular basis. Majority of Indian and Nepali citizen cross the 1850-kilometer-long border without showing any legal documents. The trafficker easily targeted people from Nepal and make heavy dominancy on the corrupt authorities. 56 In several Asian countries weak policies of political leaders and the corruption of law enforcing agencies leads to irregular migration and human trafficking. 15 Like in Iraq, Libya and Myanmar the government officials and other policy makers involve in the recruitment of human trafficking for the purpose of child soldiers and forced labor in armed forces. Armed military and other political and government policy makers have used trafficking to increase their resources and political power. 53 Most of the trafficking victims have not trust on government agencies and did not want to report their cases in police stations. For instance, one female victim told "if we go to the police station for help, I am sure they will not help". 42

Impacts of human trafficking
Human trafficking has created hostile social, physical and psychological impacts on individuals. It also has social, economic and political disorders on the system of society. 15,31,58 For instance, a study of 14 countries indicates that more than 95% of women victims had suffered by physical and sexual violence. It is also documented that 23% of Nepalese human trafficking victim girls and women were tested HIV positive. 37 Likewise, 33% of psychical violence cases of human trafficking victims reported from Cambodia. Similarly, in south Asian countries a large number of men, women and children i.e., 22% to 49% experienced physical and sexual violence. 59 It was observed during the collection of data from Cambodia, Thailand and Vietnam, that majority of men victim respondents had experienced physical violence (e.g. Beaten, kike, slapped, dragged and push). While women and children highly observed in sexual violence. 58 Furthermore, the victims of human trafficking such as women, men and children are noted in the high risk of psychological wellbeing. 60,61 Traffickers use the tactics of threats to control the minds of victims. They usually threaten their families to violence and deaths. Degradation is the most powerful psychological tactic, used by traffickers to control the victim's behaviour. Likewise, the traffickers insulted and humiliated the victims. They also destroyed their privacy and dignity and treated them like animals. For example, a victim of trafficking told that "it was very difficult, he was treating me like a dog". 61 However, in different studies the trafficking victims commonly documented psychological issues including, stress, anxiety, depression, nightmares, insomnia, personality disorder or chronic. A recent study examined 98% trafficking victims have at least one psychological disorder. It is also reported that because of these psychological problems many of victims commit suicide. 62,63 In addition, human trafficking activities also create huge impacts on overall society. In every society, traffickers search for targeted young women and men who are looking for a job or education opportunities. For example, after the victimizations, large numbers of Indian victims do not want to return to their home countries, because of social stigmatization, threat calls of traffickers and bad economic condition. 60

Discussion and conclusion
Human trafficking is a global phenomenon. Its dimensions vary from one country to another, but it usually creates huge vulnerability for individual and communities. This scoping review blended advanced knowledge about the issue of human trafficking in Asian countries, including general overview, the prevalence and its causes and socio-health implications. In a nutshell, during this review it is concluded from the findings that majority of Asian countries i.e., India, Pakistan, Thailand, Myanmar, Burma, Afghanistan, Bangladesh, Nepal, Iraq, Syria, Uzbekistan, North Korea, Bhutan, and Sri Lanka were found to be the most vulnerable ones in the context of sex, forced labor and debt bondage trafficking.
It was further discovered that in these countries, different social, economic and political elements contribute to force individuals towards victimization of human trafficking. 32 The lives of the victims are always at risk. Likewise, many studies reported that trafficking in persons is a serious infringement of human rights. The main intention of the traffickers is to sexually, physically, psychologically and forcefully exploit the victims. The victims of child trafficking specifically girls, are trafficked into different commercial sex industries, massage centers, hotels and private locations. Because of sexual exploitation, massive number of young girls, women and children are suffering with HIV/AIDS. [64][65][66] Furthermore, after victimization, the process of returning back to the society and living in a normal life situation is a big challenge for human trafficking victims. It is to be noted that many of them commit suicide because of anxiety, stress, depression and fears of societal stigmatization. 66 In this article different studies highlight the high level variability of victims in the shape of severe health outcome and violence. In addition, many scholars affirmed that corruption, weak government and political policies are deeply intertwined in the Asian region. Traffickers have organized networks and links. In many Asian countries, even law enforcement officer's support the traffickers. In this way, many corrupt government officers and traffickers make huge illicit profits. 67 Meanwhile, gaps still exist in our understanding of the outcomes to developing future clarity. This still needs more policies and practices in Asian region to increase the identification of victims and expose the underground network of traffickers. It is somehow heartening to note that at the global stage, plethora of international legal framework took birth in the pursuit to combat human trafficking such as the Protocol to Prevent, Suppress, and Punish Trafficking in Persons, Especially Women and Children and the Protocol Against the Smuggling of Migrants by Land, Sea and Air which are part of the United Nations Convention Against Transnational Organized Crimes. 34 These legal instruments are the impetus aimed to provide effective action to prevent and combat human trafficking apart from providing protection to the victims and swift punishments to the perpetrators. More recently in year 2015, ASEAN Convention Against Trafficking in Persons was signed by all the ASEAN leaders at the 27 th ASEAN Summit in Kuala Lumpur, Malaysia which saw a positive progressive move by the countries in the ASEAN region to address human trafficking issue seriously. This particular Convention inter alia, sets out inter-state cooperation on border control, mutual legal assistance and criminal extradition, law enforcement in the cross-border context and some standards on victim assistance and protection including safe repatriation to the home countries. 68 Therefore, premised upon the discussion and analysis above that the author recommends the following suggestions to the government, non-government policy makers. These recommendations also provide directions to academic scholars for future research.

Limitations and policy recommendations for future research
This scoping review has several limitations. Firstly, information gathered regarding the link between human trafficking with prevalence, causes and impacts in Asian countries was only obtained from the Sage Journal Online, Wiley Online, Hein Online, Taylor & Francis Online, Web of Science, and Scopus literature and published from January 2015 to June 2022. Secondly, this review was limited to those articles and international reports which must have a focus on or a link with Asian countries and also have link with human trafficking and illegal migration. Therefore, it is possibility that some high-quality research articles might have been excluded from this scoping review process.
Apart from the limitations, there are still gaps in our knowledge and challenges to developing future clarity. Firstly, it is highly important that every Asian country needs to imbue an operative surveillance system to better understanding the essence and immensity of human trafficking and make effective interventions. Furthermore, government officials and policy makers need to understand the seriousness of trafficker's violations and make a high-level committee to expose the corrupt officials and those who cooperate the traffickers. Likewise, this is still a need that future research should contribute to increase the identification of human trafficking victims. Additionally, every government and non-government agency and academic scholar needs to develop awareness programs on local and international basis regarding the illicit activities of human trafficking. These awareness campaigns must educate the local people of all ages and gender about the risks of traffickers. Besides, empowerment program should be given to the trafficking victims. They need a transit shelter, counselling, and training program to handle trauma and continue their life survival. Finally, human traffickers and individual who abet them deserves severe punishment for violating human rights.

Data availability
Underlying data No data are associated with the article.

Sunee Kanyajit
Faculty of Social Sciences and Humanities, Mahidol University, Salaya, Thailand In my opinion, this article is very interesting because the researchers select other academic articles from a variety database. Consequently, this article is reliable. Also, meta-analysis is appropriate with this article. However, I suggest that this article should add data and information as follows.
In the methodology section, the article gathers a lot of data from variety database and extract to main issue. So, please explain and clarify the how the methodology was conducted.
In result section, the article shall explain data in Table 1. Also, please explain reason 1, reason 2 and reason 3. Especially, the reason 3 must clarify how to find out. The result shall increase more information. Increasing data in result section make this article to be perfect and beneficial for reader.
Are the rationale for, and objectives of, the Systematic Review clearly stated? Yes

Is the statistical analysis and its interpretation appropriate? Yes
Are the conclusions drawn adequately supported by the results presented in the review? Yes Competing Interests: No competing interests were disclosed.
I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.
Yes countries. South Asia countries include Pakistan, Bangladesh, Nepal and India and are not members of Asean countries. The term Asian is different from Asean and there must be a clear distinction made between Southeast Asian countries and South Asia countries. Asean on the other hand is an association of 10 (+1) Southeast Asian countries that works together to promote political, economic, and cultural growth. In this sense, the title itself is misleading and incorrect.
One of the greatest challenges in trafficking is the data obtained from various sources as there's no standard data in assessing human trafficking victims or human trafficking activities. There's been a plethora of literature and critiques on this. Each organization would have its own variables in collating their data and all these were not discussed.
Also, human trafficking can be carried out by individuals, groups or organised crime and not just organised crime per se as referred to in this article. I find this troubling and misleading. There's also no mention of the recruiters that could also involve family members, relatives and friends.
There is plenty of misleading information in this article particularly on how trafficking activities are carried out. While trafficking could also include involuntariness, many victims voluntarily migrate to other countries but eventually find themselves trafficked. This was not discussed in the article when this is the most prevalent form of deception in trafficking. The term deception would also include under payment or non-payment of wages, poor living conditions or conditions of work that differs from what was promised earlier which does not necessarily mean poor conditions. It can mean different working hours, clients, type of work, places, etc. Although the authors are all from Malaysia or based in Malaysia, there was no mention of the Malaysian Anti Trafficking and Anti Smuggling of Migrants Act 2007, neither were there references made to this Act. The annual US Trafficking in Persons Report was not mentioned in this article when this report forms an integral part of the assessment of trafficking globally.
The methodology was vague, clunky, and incomplete. There needs to be more discussion and understanding on what amounts to methodology and methods with regards to conducting document analysis, data analysis, content analysis, thematic analysis and secondary analysis in trafficking. Overall, the paper is rather weak and contains many misleading statements. The article needs to be re-written to reflect the true nature of human trafficking. More research and analysis is needed.

Is the statistical analysis and its interpretation appropriate? No
Are the conclusions drawn adequately supported by the results presented in the review? No Competing Interests: No competing interests were disclosed.
I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.
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