Lead Poisoning and Contamination in Vietnam

By Lan Nguyen, Bachelor of International Relations, University of Social Sciences and Humanities Ho Chi Minh City Vietnam; Student, Masters of Human Resource Management, University of Technology, Sydney; Intern at The LEAD Group. Late 2013

INTRODUCTION

Lead poisoning has been recognised as a serious health problem all over the world for decades. However, in Vietnam the community is still lacking knowledge of lead poisoning and lead contamination; and this has and will continue to result in a number of negative consequences. October 20-26th 2013 marked the Inaugural International Lead Poisoning Prevention Week of Action, and while 35 countries participated in this World Health Organisation (WHO) and United Nations Environment Programme (UNEP) initiative, Vietnam was not one of them.

(See the map of participating countries at https://www.google.com/fusiontables/embedviz?q=select+col1+from+1OG9aRBB5lL
XEDiZ2ZTr8uOd4rRbbmRu_rFb4a9U&viz=MAP&h=false&lat=32.9723045620657&lng=-
70.58009375&t=1&z=3&l=col1&y=3&tmplt=4&hml=ONE_COL_LAT_LNG and click on the red dots to read the Lead Week of Action activities in each country.)

Therefore, this report’s major purpose is to raise public awareness in Vietnam, of the harmful effects of lead with some detailed cases as well as data from scientific research conducted in Vietnam.

First I report the results of a survey on childhood blood lead levels in the southern area of Vietnam; then following is a review of associated risk factors with specific examples in certain areas, covering mining and recycling activities, traditional remedies, food and consumer products as significant sources of potential lead exposure in Vietnam.

BLOOD LEAD LEVELS IN VIETNAM

Havens’ study (2012), titled “Childhood Blood Lead Levels and Associated Risk Factors in Vietnam”, gives a brief summary of blood lead levels dependent on the characteristics of the children enrolled in the study, and their families (see Table 1), indicating that ‘although leaded gasoline has been phased out, there are still sources of lead exposure in the environment in Vietnam more than a decade later’ (p. 32), with leaded paint, traditional medicines, metal recycling and smelting included.

Table 1 Distribution of Blood Lead Levels Relative to Major Child and Family Characteristics (n=331)

* µg/dL means micrograms per decilitre - micrograms of lead per decilitre of blood

** IQI means the inter-quartile intervals, (25th - 75th percentiles) which describe the blood lead distribution. Source: Havens 2012

Unfortunately, in relation to leaded paint, one of the major concerns in OECD countries, there is little in the way of statistics on its production, trade and waste in Asia as well as the Pacific, and Vietnam is no exception.

The following section: ASSOCIATED RISK FACTORS - discusses not only the details of three significant sources of lead exposure but also two other sources of increasing concern: food and consumer products.

ASSOCIATED RISK FACTORS

Mining activities

A study by Nguyen et al (2011) conducted at one of the largest lead-zinc mines in Northern Vietnam examines the concentrations of multiple heavy metals in some plant species as well as soil and water samples collected beside a stream, downstream from one of the mine sites. They found that ‘All the concentrations of Cu [Copper], Zn [Zinc], As [Arsenic], Cd [Cadmium] and Pb [Lead] in soil samples collected from the mine site exceeded Vietnamese standard limits for industrial soil’ (p. 1386). In particular, while the allowable Pb limit is 300 milligrams per kilogram (mgkg-1), the mean Pb concentrations for all soil sample sites ranged between 2,630 mgkg-1 and 91,800 mgkg-1. Samples from one mine site (No. 7) contained a mean Pb level of 30,700 mgkg-1 and a range of 16,900 to 77,900 mgkg-1 , whereas samples from mine site No. 1 contained a mean of 91,800 mgkg-1 and a range of 89,100 to 94,300 mgkg-1 Pb. Samples collected beside the stream downstream from No. 1 mine site, at the closest sampling site to the mine site, contained a mean of 15,000 mgkg-1 and a range from 10,300 to 19,800 mgkg-1 Pb. The most distant downstream sampling site from mine site No. 1, contained a mean of 2,630 mgkg-1 and a range of 2,190 to 3,540 mgkg-1 Pb.

Findings of another study which focused on Cho Dien mine, one of the largest lead and zinc mines in Bac Kan Province, Vietnam, indicated that ‘Pb contamination in drinking water and surface water is a major concern’ (Nguyen et al 2012, p. 263) (see more detail in Table 2 and Table 3)

Table 2 Average and range of concentrations of heavy metals in drinking water sampled around Cho Dien mine, Bac Kan Province (mg/L*) [and Vietnamese and US standard limits, for comparison]

1329/2002/BYT/QD: Hygiene Standard of Drinking Water – Ministry of Public Health, Vietnam

* mg/L means milligrams per litre, that is milligrams of lead per litre of water

** (ND-2) means results ranged from ND = Not detected, up to 2 mg/L, and so on

Source: Nguyen et al 2012

The concentration of Pb in 6 of the total 14 creek samples, mostly from sites near the mining areas, were found to be higher than the permissible Vietnamese standard of 10 mg/L value, according to Nguyen et al (2012). Also, ‘the locations where Pb concentration was higher than the allowable standard were at two bore wells near mine tailings’ (p. 258). Similarly, the Pb level in surface water was above the allowable standard at some locations near the mining area and it was even higher in comparison with that measured in drinking water.

Table 3 Average and range of concentrations of heavy metals in surface water sampled around Cho Dien mine (mg/L)

QCVN-B1 08:2008/BTNMT: National technical regulations on quality of surface water source, class B1

Note: The classification of surface water to assess water quality and control, for purposes of water use vary; A1-Good use for water supply purposes and other purposes, such as type A2, B1 and B2; A2-For the purpose of water supply but to apply the appropriate; treatment technology; preservation of aquatic plants, or other purposes, such as type B1 and B2; B1-For irrigation purposes or other purposes required or similar water quality purposes as type B2 use; B2-Transport water and other purposes with low quality water requirements.

ND: Not detected

Source: Nguyen et al 2012

Recycling activities

In developing countries, lead exposures are frequently associated with not only smelting and mining but also recycling efforts. According to Gottesfeld and Pokhrel (2011, as cited with the wrong spelling Gottsfeld, in Havens 2012, p. 1 & 2), ‘Even with the elimination of leaded fuel, elevated pediatric blood lead levels have been found in neighboring Southeast Asian countries due to other environmental lead exposures such as lead battery recycling and electronic waste (e-waste). Some of these same exposures can be found throughout Vietnam’.

Very few studies have investigated the heavy metal content in rice samples from recycling areas in the country. According to Le et al. 2009, in an aluminium waste recycling village in Van Mon – Bac Ninh, the average content of Pb in the rice samples (0,057 ppm) was found to be lower than the FAO (Food and Agriculture Organization of the United Nations)/ World Health Organization (WHO) Guidelines which is less than 0.1 ppm. However, notably, the comparison of oral and inhalation exposure estimates, also known as hazard quotient (HQ), was higher in the polluted area. In other words, lead exposure in the neighborhood area was estimated to be generally high in comparison with other neighbhourhoods some distance away, maybe more than two times higher.

These were the outcomes of a research finished in 2009 and published in 2010. However, in 2010 there are updates. ‘The Joint FAO/WHO Expert Committee on Food Additives re-evaluated lead in June, 2010 and withdrew the provisional tolerable weekly intake guideline value on the grounds that it was inadequate to protect against IQ loss.’ (WHO 2010) In other words, WHO is saying that there is no safe limit for lead in food as any lead will damage the developing human brain, at blood levels of 5 μg/dl and even lower.

Photo: High level of pollution in aluminum waste recycling village Van Mon (Yen Phong – Bac Ninh)

Source: http://vea.gov.vn/vn/truyenthong/tapchimt/nctd42009/PublishingImages/TCMT%2
0122011%2050.jpg  

Another example was in Dong Mai lead recycling village (Hung Yen province), where blood lead tests were performed on resident children under the ages of 10 years in 2012. Results showed that all of them were found having BLLs above the previously recommended 10 micrograms per deciliter (µg/dL) limit. Notably, in a further test, of 24 participating children, there were 2 cases with BLLs of ≥70µg/dL, 17 at 45-70 µg/dL, 4 at 25-44 µg/dL, and 1 at 15-19 µg/dL (baohungyen.vn 2012).

In May 2012, the USA Centers for Disease Control and Prevention (CDC) halved the blood lead reference level from 10 µg/dL to 5 µg/dL for follow up for children in the United States.

In the past, blood lead level tests below 10 micrograms per deciliter may, or may not, have been reported to parents. Identifying a child’s blood lead equal to or above 5 micrograms per deciliter means more parents should learn that their child has an elevated blood lead level. (CDC 2012)

Even though there has been increasing awareness of at-risk children, the significant issue is that lead recycling has been the major source of employment for local residents in this area. Among the cases of highest level lead poisoning, 3 year-old girl Le Phuong Ly with BLL of 73.16 µg/dl has been growing up in the highly polluted house considered as an informal recycling site. Her parent, when being asked about their intention of stopping such manufacturing or shifting it to some distance, was still undecided (baohungyen.vn 2012).

Lead in traditional remedies

The use of some Asian traditional and herbal therapies would give a daily dose of heavy metals, including arsenic, lead and mercury, when regularly taken as recommended. According to Garvey et al. (2001), lead content of these so-called ‘natural’ medicines, with a daily dose of lead in excess of 300 micrograms (µg), may increase blood lead levels and body lead burdens (see Table 4).

Table 4 Daily lead dose >300 µg per day in 54 different traditional Asian remedies

Notes: Total 32/54 (60%)

Source: Garvey et al. 2001

According to Garvey et al (2001), the daily dose for protection of public health is 30 µg of lead per day. However, Medlin (2004) emphasised that blood lead levels as low as 10 μg/dL cause adverse health effects, and that, for children under age 6, the U.S. Food and Drug Administration (FDA) recommends the rate of less than 6.0 μg lead daily from all food sources. This, in comparison with the magnitude of the daily dose that is possible when traditional medicines contain lead in excess of 300 µg per gram, indicates a high lead poisoning potential and potential for adverse health risks for those who are using these kinds of medicines – depending of course on how many pills are ingested each day.

Pandalai and Morgan (2011) further emphasise that traditional remedies, also known as Complementary and Alternative Medicines (CAM), has been little studied regarding metal content of these products specifically from Vietnam, but ‘limited data collected from other Southeast Asian countries where similar products are used and available are revealing’ (p. 296).

In Vietnam, these kinds of medicines could be a risk to public health mainly because the origins of the raw materials, the name of the traders involved, and their recipes are largely unknown. There was a sharp increase in lead poisoning among children, raising alarm at the impacts of fake oriental traditional medicines on children’s health late in 2011. In the last few months of that year, more than 130 cases, 94% of them children, were sent to the Poisons Information Center, Bach Mai Hospital, Hanoi (vietnamnet.vn 2011).

A sample of traditional remedies of unknown origins reported to contain lead.

Source: http://bachmai.gov.vn/images/stories/2010/chongdoc.jpg 

According to the Chemical Institute, of 100 samples of this medicine, 98 were reported to contain lead of 2%, and more important, some of them had more than 85% lead content (vietnamnet.vn 2011). The figure of 2% lead converts to 20,000 micrograms per gram (µg/gm), whereas 85% lead converts to 850,000 µg/gm, so, clearly, a person would not have to ingest very much of these pills before their blood lead level would start to rise and the more they ingest, the sooner they would become “a case of lead poisoning”. For every case who reaches the hospital however, there would be many more cases where symptoms may be less severe, or medical attention is not sought for other reasons, and people thus continue to take the medications because they’re unaware of the potential impacts on their long-term health and intellectual development.

Lead in food

Besides traditional therapies, food safety has been a matter of considerable public concern in Vietnam. In general, there are two major sources of this big worry, including influence of environmental contaminants and impacts of harmful chemicals used as food preservatives, colourants and flavour enhancers.

One increasing concern refers to potentially toxic element accumulation in fish and vegetables from environmental pollution in association with urban growth, agricultural growth and industrial development. For further understanding of the risk associated with human consumption, Marcussen et al (2007) and Le et al (2009) examined the concentration of toxic elements in eels and fish produced in wastewater-fed ponds of Hanoi and in freshwater from the central provinces respectively. It is emphasised that ‘among the various pollutants, heavy metals, in particular, are widespread contaminants released into aquatic systems from numerous anthropogenic sources. Some metals are known to be toxic even at low concentrations, including arsenic, cadmium, mercury, and lead’ (Le et al 2009, p. 70). The maximum metal levels in fish were found to be far lower than the permissible values for fish consumption, suggesting that any serious health risk for public health were not clear.

Another significant aspect is concerned with the increasing use of harmful chemicals on food. This does not necessarily simply mention chemicals such as pesticides, antibiotics and hormones that are used in plant and animal farming to boost production and ensure adequate food supply. More importantly, it has been discussed that unhealthy processed foods greatly outnumber unadulterated healthy foods. According to Natural Medicine College (2013), more than 75% of supermarket shelves are stocked with packaged and processed foods today. Notably, many newspaper articles have recently described plenty of harmful chemicals used on food that are available to buy in the area. For example, a kind of industrial powder is said to be widely used instead of bones in soups at small restaurants in order to cut electricity consumption.

Health risks ignored, industrial powder has been widely used in foods

Source: http://us.24h.com.vn/upload/3-2013/images/2013-08-05/1375665707-ham-thuc-an1.jpg

This powder is believed to contain heavy metals and other toxic elements but as many people have not had much knowledge of that, it has been very popular among restaurant owners (Ngoc Mai 2013).

Lead in consumer products

It is reported that the general risk of lead in consumer products is still prevalent in the region. Data collected by Murao and Ono (2012) shows that Vietnam is among various Asia Pacific countries that still use lead for their products (see Table 5).

Table 5 Existing use of leaded paint. KEY - Y: yes; N: no; NA: information not available

Source: Country presentations at the 2nd GAELP presentation by Mendoza, June 2012/Bangkok (Murao and Ono 2012)

During 2007 there were numerous recalls of name-brand toys in the United States because of lead paint contamination including products from China, Korea, India, Peru, Taiwan, and Vietnam. Lead contamination rates were further analysed, giving the results that of the tested 95 samples, 12 items were reported to have high lead content, exceeding the current US regulatory standard (Weidenhamer 2009). These findings suggest that toys and other consumer products deserve more attention from government agencies as well as manufacturers and retailers.

Another case that raised questions for government agencies in seeking to limit lead exposure was lead contaminated mugs, glasses and cups imported from China early in 2011. In more detail, Quality Management Institute’s representative emphasised, ‘Tests of samples show that most of them have high contents of heavy metals including lead in paint.’ However, at that time the lead content of such imports had not been limited in Vietnam’s existing regulations, so the only thing government agencies could do was to recommend consumers not use these products (Thanh Xuan & Vu Van Anh 2011).

  CONCLUSION

This brief review of research and e-articles on potential health risks associated with lead poisoning in Vietnam cannot present comprehensive information since very little data is available. However, it can be seen that Vietnam’s marked industrialisation without sufficient regulations is of outstanding importance. Some mentioned scholars provided further emphasis for the recommendation that, ‘while government institutions may need to be strengthened, and environmental regulations need to be in place, true on-the-ground improvement in environmental quality in Vietnam and in many other developing countries requires an increased focus on promoting public awareness of industrial environmental issues’ (Wahlberg & Nguyen 2008, p. 712).

RECOMMENDATIONS

As mentioned above, the most significant issue related to lead poisoning in Vietnam is the lack of knowledge of lead exposure among the community. Mentioning about lead poisoning monitoring, Havens (2012) states ‘Vietnam does not appear to have any form of routine surveillance in place, even though there has been increasing awareness of at-risk children, particularly around lead recycling and craft villages. I could not find any information in English medical literature or in discussion with Vietnamese personnel such as physicians and environmental scientists regarding any form of lead assessment or prevention programs in the country. There does not appear to be any public health movement to remediate any of the current lead exposures’ (p. 2).

Hence it could be concluded that the government agencies face important roles to take the first step in raising awareness. Under this circumstance, Model National Public Health Policy on the Prevention of Lead Poisoning by Elizabeth O’Brien and Anne Roberts, The LEAD Group Inc., Australia would be an effective tool. According to The LEAD Group’s Model Lead Policy, ‘the first step in implementing a national policy for preventing lead poisoning in a population is to do a national blood lead level survey of all ages’. Follow up should occur for every blood lead level above 5 µg/dL. That is, the national survey should investigate all cases above 5 µg/dL and determine the likely lead sources by testing food, water, consumer product, traditional medicines, soil, dust, etc.

These investigations are fundamental for the government to develop any health policy for the prevention of lead poisoning in Vietnam. With the available data, it will be easier to apply following steps as suggested in the Model Lead Policy.

Further, in order to prepare for participating in the 2014 International Lead Poisoning Prevention Week of Action, national governments and NGOs in every country could usefully refer to the WHO/UNEP briefing for Lead Week of Action event organizers, listed at http://www.unep.org/hazardoussubstances/LeadCadmium/PrioritiesforAction/LeadPaints/
FocalAreasofWork/GAELP/tabid/106381/Default.aspx and linked to http://www.who.int/ipcs/assessment/public_health/briefing.pdf 

REFERENCES/FURTHER READING

Baohungyen.vn (2012) Hơn 100 trẻ em xã Chỉ Đạo bị nhiễm độc chì: Hệ lụy từ nghề [TRANSLATION: Childhood lead poisoning in Dong Mai lead recycling village & the apparent source of exposure] [IN VIETNAMESE], May 2012 http://www.baohungyen.vn/xa-hoi/201205/Hon-100-tre-em-xa-Chi-dao-bi-nhiem-doc-chi-He-luy-
tu-nghe-100232/

Centers for Disease Control and Prevention (CDC), USA (2012) Fact Sheet: Blood Lead Levels in Children www.cdc.gov/nceh/lead/ACCLPP/Lead_Levels_in_Children_Fact_Sheet.pdf

Garvey G.J. et al (2001) Heavy metal hazards of Asian traditional remedies International Journal of Environmental Health Research, March 2001, ABSTRACT AT http://www.ncbi.nlm.nih.gov/pubmed/11260788

Gottesfeld, P. & Pokhrel, A.K. (2011) Review: Lead Exposure in Battery Manufacturing and Recycling in Developing Countries and Among Children in Nearby Communities in Journal of Occupational and Environmental Hygiene, September 2011 http://www.okinternational.org/docs/Gottesfeld%20JOEH%202011%20final.pdf

Havens D. (2012) Childhood Blood Lead Levels and Associated Risk Factors in Vietnam, University of Washington, Thesis (Master's) https://digital.lib.washington.edu/researchworks/handle/1773/21929

Le A.N.  et al. (2009) Nghiên cứu chỉ số liều lượng rủi ro của chì (Pb) từ nguồn lương thực tại làng nghề tái chế nhôm Văn Môn - Bắc Ninh [TRANSLATION: Assessment of Pb Contamination in food from the aluminum waste recycling village in Van Mon - Bac Ninh] [IN VIETNAMESE] Journal of Science (Natural Sciences and Technology), Vol. 26, August 13, 2009 http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/9942

Le Q.D. et al (2009) Heavy Metals in a Tropical Eel Anguilla marmorata from The Central Part of Vietnam in Water, Air, and Soil Pollution, March 19, 2009, ABSTRACT AT http://link.springer.com/article/10.1007%2Fs11270-009-0027-7#

Marcussen H. et al (2007) Food safety aspects of toxic element accumulation in fish from wastewater-fed ponds in Hanoi, Vietnam in Tropical Medicine and International Health, December 2007 http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3156.2007.01939.x/pdf

Medlin J. (2004) Sweet Candy, Bitter Poison in Environmental Health Perspectives , Vol. 112 No. 14, October 2004 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1247598/

Murao S. & Ono K. (2012) Current Status And Future Of Lead-Based Paints And Pigments In Asia And The Pacific [INTERIM REPORT] in The United Nations Environmental Programme Regional Office for Asia and the Pacific (UNEP-ROAP) and National Institute of Advanced Industrial Science and Technology (AIST), September 2012 http://www.unep.org/hazardoussubstances/Portals/9/Lead_Cadmium/docs/GAELP/Second
Meeting/Interim_UNEP_AIST-as%20of%2018Sep-final-clean.docx

Natural Medicine College (2013) The 15 Ingredients You Do Not Want in Your Food, http://www.naturalmedicinecollege.ca/natural-medicine-library/6-ingredients-you-may-
not-want-in-your-food/

Ngoc Mai (2013) Hầm thức ăn bằng... chất tẩy! [TRANSLATION: Industrial Powder Has Been Widely Used In Foods] [IN VIETNAMESE], August 5, 2013 http://us.24h.com.vn/suc-khoe-doi-song/ham-thuc-an-bang-chat-tay-c62a562296.html

Nguyen T.H. et al (2011) Uptake of metals and metalloids by plants growing in a lead zinc mine area, Northern Vietnam in Journal of Hazardous Materials 186, August 2011, ABSTRACT AT http://www.ncbi.nlm.nih.gov/pubmed/21227580

Nguyen T.T.H.et al (2012) Environmental contamination of arsenic and heavy metals around Cho Dien lead and zinc mine, Vietnam in Journal of Water and Environment Technology Vol. 10 No. 3, April 17, 2012 https://www.jstage.jst.go.jp/article/jwet/10/3/10_253/_pdf

Pandalai S.L. & Morgan B.W. (2011) Case Files of the Emory University Medical Toxicology Fellowship: Inhalational Mercury Toxicity from a Traditional Vietnamese Product in Journal of Medical Toxicology, November 10, 2011 http://link.springer.com/article/10.1007%2Fs13181-011-0180-4#page-1

Thanh Xuan & Vu Van Anh (2011) Tràn lan cốc thủy tinh nhiễm chì [TRANSLATION: Lead contaminated mugs, glasses and cups imported from China] [IN VIETNAMESE] Báo Nông thôn Ngày nay, April 15, 2011 http://danviet.vn/tran-lan-coc-thuy-tinh-nhiem-chi/39607p1c25.htm

Vietnamnet.vn (2011) Fake oriental medicine harms children in VietNamNet/Viet Nam News, November 29, 2011 http://english.vietnamnet.vn/fms/society/15614/fake-oriental-medicine-harms-children.html

Wahlberg N.H.T & Nguyen L.T. (2008) Environmental regulatory failure and metal contamination at the Giap Lai pyrite mine, Northern Vietnam in Journal of Environmental Management, March 2008, ABSTRACT AT http://www.ncbi.nlm.nih.gov/pubmed/17287069

Weidenhamer J.D. (2009) Lead contamination of inexpensive seasonal and holiday products in Science of The Total Environment 2009, ABSTRACT AT http://www.sciencedirect.com/science/article/pii/S0048969708011479

World Health Organisation (2010) Childhood Lead Poisoning Booklet http://www.who.int/ceh/publications/leadguidance.pdf