By : SABAHKINI.NET SPECIAL UNIT
AS MALAYSIA is moving to becoming a newly industrialized nation, it is a fact that the degradation of the natural environment happens at a pace even faster than that of the country’s industrialization. And while in the West, governments have imposed strict emission controls for heavy metals such as lead and even banned it from gasoline, the governments of developing countries often feel that environmental protection is a luxury they can’t afford yet.
Numerous studies have suggested that even low lead concentration in children could account for a significant proportion of school failures, delinquent behaviour and ultimately impaired productivity in their adulthood. Since lead serves no useful physiological functions, its accumulation is often known to be potentially toxic to several organ systems. To date, more is known about lead toxicity than about any other metal.
DEMAND FOR LEAD
Being very soft and pliable and highly resistant to corrosion, lead was ideal for use in plumbing as well as for the manufacture of pewter. In the early 20th century the automotive industry took off and new areas of consumption – batteries and petrol – created an enormous market. Storage batteries remain the main outlet.
In 2007, the total world production of lead was 8,084,900 tonnes per annum (2007) where Asian countries are the major supplier of lead (48%) followed by the America (26%) and Europe (22%) and lead is mostly used to produce battery (lead acid battery) (71%) (“Lead – Industry Usage” published by the London Metal Exchange, 12 April 2010 – Appendix 1).
Lead is one of the most recycled metals in the world, ensuring that a constant supply is available for end-users. A very efficient lead recycling factory can reproduce up to 95% rate of lead. The ease of recycling helps to cap prices; when prices are rising consumers are able to easily bring in scrap lead and convert it into cash.
Furthermore, lead remains a low cost alternative to other similar metals which is helping to keep demand up in poorer emerging countries (“BEST Battery Program Aims to Reduce Lead Battery Poisoning in Asia” published by Planet Green, 01 January 2009 – Appendix 2).
LEAD IN OUR DAILY ENVIRONMENT
It is practically impossible to have a 100% lead free home. The subtlety and pervasive nature of lead exposure could be gauged from the number of sources readily available in our daily surrounding. It ranges from soil to paints; lead glazed ceramics to toys, from furniture to canned foods with exposed lead solder and, from antique pewter to metallic objects and equipment.
It is used to make almost all of the early utensils, storage containers and vessels used for cooking. It is also present in the soil, water, food, air and numerous industrial products. Since lead is found in many household items that we use every day, we might not realize the potential dangers in our home caused by the presence of lead. Old paint, old pipes and toys are most commonly known for having lead related danger.
Ceramic tiles typically found in older bathrooms might contain dangerous amounts of lead. Ceramic toothbrush holders may also contain lead. Common everyday garden hoses are often made from recycled materials.
Many of the common garden hoses found in stores has a disclaimer on the packaging warning of possible lead content. There are hoses that do not contain lead on the market, but they are a little more expensive (“Products We Use Daily that Contain Lead” published by Associated Content, 23 January 2008 – Appendix 3).
LEAD TOXICITY AND THE HAZARD IT POSES
The toxicity of lead is well known, especially after the recent Chinese lead paint toy fiasco. Due to this and other health concerns, most manufacturers are taking steps to phase out the metal’s usage in many applications, specifically in paint, electric circuits and auxiliary car uses.
Low doses of lead can cause behavioural problems, hyperactivity, and learning disabilities. Higher levels of lead in our blood system can cause seizures, comas, brain damage, and even death. Lead exposure and its dispensation into the atmosphere are principally due to an industrial environment, not to natural processes (“Five Reasons Why The Lead ETN (LD) Is Sinking Like . . . Well, Lead” published by Daily Markets, 03 March 2010 – Appendix 4).
Since lead serves no useful physiological function, its accumulation is often known to be potentially toxic to several organ systems. Lead can enter into the food chain in soil and can be unknowingly ingested. When introduced into the body either by ingestion or inhalation, the lead pigments are separated and the body is fooled into accepting them as normal, useful elements such as calcium and iron.
Once incorporated into the body's chemistry, it possesses the ability to inhibit the normal function of the various organs in the body. With exposure and/or re-exposure to lead, the amount of lead in the body can further increase. It is not possible for the body to dispose of lead by itself. Thus the lead will remain stored in the body especially in the bones and kidneys.
The effect of exposure is therefore cumulative. The majority of lead poisoning cases occur from the absorption of inorganic lead (“Lead Exposure and the IQ of Children” published by The Sun, 17 October 1995, quoted by the National Poison Centre, 2008 – Appendix 5).
The decades-old controversy over the use of lead as a fuel additive is a mere footnote to centuries of controversy over this remarkably useful but also insidiously deadly metal. The ancients regarded lead as the father of all metals.
The Romans were aware that lead could cause serious health problems, even madness and death. However, they were so fond of its diverse uses that they minimized the hazards it posed. Romans of yesteryear, like Americans of today, equated limited exposure to lead with limited risk.
What they did not realize was that their everyday low-level exposure to the metal rendered them vulnerable to chronic lead poisoning, even while it spared them the full horrors of acute lead poisoning. The result, according to many modern scholars, was the death by slow poisoning of the greatest empire the world has ever known (“Lead Poisoning: A Historical Perspective” published by the United States Environmental Protection Agency, May 1985 – Appendix 6).
The deadliness of tetraethyl lead was confirmed in the summer of 1924. Workers engaged in producing the additive fell sick and died at several refineries in New Jersey and Ohio.
Indeed, no compulsory standards were set for the industry until the early 1970s when EPA began its long, hard struggle to phase down lead levels in U.S. gasoline. EPA’s health document on the subject, "EPA's Position on the Health Implications of Airborne Lead," released on November 28, 1973 confirmed that lead from automobile exhaust was posing a direct threat to public health. In response, from 1975, U.S. automakers equipped new cars with pollution-reducing catalytic converters designed to run only on unleaded fuel (“Lead Poisoning: A Historical Perspective” published by the United States Environmental Protection Agency, May 1985 – Appendix 6).
Children are the most vulnerable group to lead intoxication as they tend to absorb more lead than adults. Children are indeed vulnerable by the very fact that they can absorb as much as 50 per cent of ingested lead compared to 8 - 10 per cent in the adult population.
The World Bank warned that as many as 18 million children may face permanent brain damage associated with excessive lead in the body (“Heeding The ‘Smog’ Signal About Lead Poisoning” published by the National Poison Centre, 1997 – Appendix 7). The amount absorbed can be higher if the children also suffer from malnourishment and deficiencies of some elements such as iron, calcium and zinc (“Lead Exposure and the IQ of Children” published by The Sun, 17 October 1995, quoted by the National Poison Centre, 2008 – Appendix 5).
Pathways for the ingestion of lead by children include the habit of putting their hands or other objects covered with lead dust into their mouths, eating paint chips or soil that contains lead, breathing in lead dust especially during renovation that disturbs surfaces with lead-based paint, and playing in lead- contaminated areas.
Lead can also be brought back from the parent's workplace such as battery plants (“Children Vulnerable to Lead Poisoning” published by The New Straits Times, 21 November 1997, quoted by the National Poison Centre, 2008 – Appendix 8).
Acute lead poisoning can occur to adults if they are directly exposed to large amounts of lead through inhaling dust, fumes or vapours dispersed in the air. However, chronic poisoning from absorbing low amounts of lead over long periods of time is a much more common and pervasive problem.
Lead can enter the body through the lungs or the mouth, and over long periods can accumulate in the bones. Furthermore, among adults, ingestion of lead during fasting results in a greater absorption of lead than lead were ingested in food (“Effect of Food Intake and Fasting On The Gastrointestinal Lead Absorption in Human” by Rabinowitz MB; Kopple JD; & Wetherill GW, published by Am J Clin Nutr; 33:1784-88, 1980 – Appendix 9).
It can cause health problems such as difficulties in pregnancy, reproductive problems in men and women, high blood pressure, digestive problems, nerve disorders, memory and concentration problems and muscle and joint pain (“Heeding The ‘Smog’ Signal About Lead Poisoning” published by the National Poison Centre, 1997 – Appendix 7).
Symptoms of lead poisoning at all ages are not specific and often go unrecognized. In a toddler, anorexia is the earliest symptom. Other emerging problems may include occasional vomiting, irritability and unwillingness to play.
More serious signs include persistent vomiting, peripheral nerve weakness, convulsions and coma (“Heeding The ‘Smog’ Signal About Lead Poisoning” published by the National Poison Centre, 1997 – Appendix 7). Children who are lead-poisoned can suffer from damages to the brain and nervous system that may cause behavioural and learning problems. It may also retard the physical development of children.
Other related problems are hearing difficulties and kidney damage. In large doses, lead can cause blindness, brain damage and even death (“Lead Exposure and the IQ of Children” published by The Sun, 17 October 1995, quoted by the National Poison Centre, 2008 – Appendix 5).
There is now evidence that lead is harmful at blood levels once thought safe previously. Studies have shown that groups of children with high lead levels are likely to have lower IQ scores, slower development and more attention-deficit problems than children with lower lead levels.
Unborn children can also be exposed to lead through their mothers. Harmful effects through this maternal transfer include premature birth, smaller babies, decreased mental ability in the infant, learning difficulties and reduced growth (“Children Vulnerable to Lead Poisoning” published by The New Straits Times, 21 November 1997, quoted by the National Poison Centre, 2008 – Appendix 8).
RESEARCH RESULTS ON HEALTH DETRIMENTS CAUSED BY LEAD POISONING
A study on Neurobehavioral Test Performances to 141 male workers from 3 major ethnic groups; Malays, Chinese and Indian was carried out where the participants were divided into 2 groups of highly exposed group with blood lead levels (PbB) ≥ 40 g/dl and low exposed group of PbB < 40 g/dl according to the World Health Organisation’s biological exposure index.
Results from this study shows that lead can cause dysfunctions of the central nervous system in terms of processing speed, attention, concentration, memory functions and motor steadiness. Lead has also given higher subjective complaints of weakness of lower limbs and loss of appetite in the highly exposed group. These findings of lead toxicity to neurobehavioral performances and the subjective symptoms were consistent with many other studies.
The applications of the neurobehavioral tests can also detect the early toxic effect of lead, which enhances the prevention strategies before leading to any irreversible damage. This finding highlights the importance of the neurobehavioral tests which can be incorporated in the medical surveillance programme of Lead Regulations Malaysia (“Neurobehavioral Performances Among Lead Exposed Workers In Malaysia: An Early Detection of Lead Toxicity” by Mazrura Sahani & Noor Hassim Ismail, published by the Institute for Medical Research, Kuala Lumpur, June 2005 – Appendix 10).
A study on lead exposure of pre-school children from the West Coast of Sabah in April 1996 was carried out with the aim to investigate the implications arising from lead poisoning among pre-school children. The objective of the study was to:
- identify the level of lead poisoning in pre-school children from the West Coast of Sabah
- identify the high exposure risk kindergartens
- identify the population of children affected by lead poisoning
For this purpose thirteen (13) kindergartens from six (6) districts from the West Coast of Sabah were randomly selected for inclusion involving four hundred and thirty-five (435) children. Blood samples were obtained and analysed. Three (3) important conclusions were drawn from the results obtained:
(i) The estimation of the level of lead exposure suggested that as many as 6.9% of the blood samples analysed from the children contained lead in excess of 10 mcg/dL compared with 20.7% between 5-9.99 mcg/dL and 72.4% between 0-4.99 mcg/dL.
(ii) Based on a concentration of 10 mcg/dL, three (3) districts namely Ranau, Kota Belud and Tuaran can be classed as high exposure regions and the percentage of children exposed to lead in these three areas are much higher compared to the other districts. The kindergartens involved in these areas have been identified. The highest concentration of lead detected in these districts was 18.8 mcg/dL.
(iii) The population of children at high risk suggested that age is a factor in lead exposure. Children of age six (6) years showed relatively higher levels of lead as compared to the younger population. It is evident that lead absorption was continuous over time. There was no gender difference observed (“Heeding The ‘Smog’ Signal About Lead Poisoning” published by the National Poison Centre, 1997 – Appendix 7).
16. The study proposes that although in general the level of lead poisoning among pre-schoolers can be considered as not critical, there were however nearly 7% of the children in the study group who required serious attention. They require continuous monitoring.
It is proposed that a follow-up action be taken especially for the one hundred and twenty four (124) children who have lead concentrations in excess of 5 mcg/dL and another twenty (20) new samples. It is also proposed that a long term action plan be undertaken to reduce the instances of lead exposure in the West Coast of Sabah in particular, and in the whole of Sabah in general (“Heeding The ‘Smog’ Signal About Lead Poisoning” published by the National Poison Centre, 1997 – Appendix 7).
A follow up test conducted between 21-25 April 1997 revealed that:
(i) 48 children or 29.8% contained lead in excess of 10 mcg/dL, 81 (56.3%) children between 5-9.99 mcg/dL and 20 (13.9%) between 0-4.99 mcg/dL;
(ii) there were obvious changes in the lead content contained in the blood samples tested. Some samples have shown a decreased and increased. In cases which shows a decrease, their level are still alarming since they are in excess of 10 mcg/dL; and
(iii) new samples of children who are siblings to the children who tested positive in the earlier test shows that they have also been exposed to lead.
Conclusion: the numbers of children affected are on the increase (“Kajian Susulan Pendedahan Plumbum Di Kalangan Kanak-kanak Pra-Sekolah Di Kawasan Pantai Barat Sabah” published by Yayasan Sabah & the National Poison Centre, 1997 – Appendix 11).
A research was also carried out on lead contamination in vegetables. Vegetables are vital to human diet as they contain essential components needed by the human body such as carbohydrates, proteins, vitamins, minerals. Consumption of vegetables is one of the pathways by which heavy metals enter the food chain.
Excessive accumulation of dietary heavy metals such as cadmium, plumbum (lead) and chromium can lead to serious health problems. Heavy metals persist in the environment, are non-biodegradable and have the potential to accumulate in different body organs.
Various studies have been conducted on metal assessment in edible vegetables, crops and also soils show the ability of crops to take up heavy metals (“Relationship between Metals in Vegetables with Soils in Farmlands of Kuching, Sarawak” by Devagi Kanakaraju; Nur Aa’in Mazura; & Awang Khairulanwar, published by the Malaysian Journal of Soil Science Vol. 11 : 57 – 69 (2007) – Appendix 12).
The Malaysian dietary guidelines recommend five servings of fruits and vegetables per day for adults to maintain good health. Largely, due to awareness of vegetable consumption, large quantities of vegetables are consumed to obtain sufficient nutrients as body supplements and this has resulted in human beings being exposed to risk from contaminated soils and vegetables.
A study was conducted to investigate heavy metal uptake in cultivated leafy and fruit vegetables from two farmlands in Siburan and Beratok, Sarawak. Beratok is located nearer to the roadside compared to Siburan which is located far from the roadside. Higher metal concentrations were anticipated to occur in Beratok.
Metal analyses in the edible parts of vegetables were carried out (“Relationship between Metals in Vegetables with Soils in Farmlands of Kuching, Sarawak” by Devagi Kanakaraju; Nur Aa’in Mazura; & Awang Khairulanwar, published by the Malaysian Journal of Soil Science Vol. 11 : 57 – 69 (2007) – Appendix 12).
The result of the study shows that generally, leafy type vegetables accumulated higher level of metals compared to fruit type and this was further proven by statistical analysis. A previous study has shown that leafy vegetables accumulate more metals compared to other vegetables.
Metals in different parts varied between the types of vegetables. This may be attributed to the variation in heavy metals uptake by different types of vegetables. High concentrations of essential elements (Fe, Co, Cu, Mn and Zn) and non-essential metal (Pb) were found in the leaves of kale at Beratok.
Plumbum showed a tendency to concentrate in leaves of the vegetables compared to other parts at Siburan and Beratok. Metal levels in different parts of green mustard and white mustard grown at both places did not show any difference.
The potential source of plumbum could be due to gas emission from traffic as the Beratok farmland is located near the road way (“Relationship between Metals in Vegetables with Soils in Farmlands of Kuching, Sarawak” by Devagi Kanakaraju; Nur Aa’in Mazura; & Awang Khairulanwar, published by the Malaysian Journal of Soil Science Vol. 11 : 57 – 69 (2007) – Appendix 12).
Concentrations of metals in the vegetables at Siburan and Beratok were influenced by the water used for irrigation, spraying methods and also the fertilisers used. At Siburan, irrigation water from nearby Sungai Ribit was applied to the vegetables.
The accumulation effect depends strongly on the crop’s physiological properties, the mobility of the metals, and the availability of metals in soils and surface deposits on the parts of vegetables exposed to polluted air. The toxic element, plumbum was found in the least concentrations compared to other metals analysed.
However, the level of plumbum exceeded the Malaysian Food Act 1983 guidelines (“Relationship between Metals in Vegetables with Soils in Farmlands of Kuching, Sarawak” by Devagi Kanakaraju; Nur Aa’in Mazura; & Awang Khairulanwar, published by the Malaysian Journal of Soil Science Vol. 11 : 57 – 69 (2007) – Appendix 12).
The levels of metals in similar vegetable species differed between the sampling sites at Siburan and Beratok. It is suggested that soil properties between the sampling sites contributed to this variation. There are various sources that could attribute to metal contamination and contamination process which could have taken place during pre-harvest and post harvest process.
Sources during pre-harvest include usage of compost, fertilisers and pesticides, chicken dung and water used for irrigation, while sources during post harvest include contamination through air and also during transport to market (“Relationship between Metals in Vegetables with Soils in Farmlands of Kuching, Sarawak” by Devagi Kanakaraju; Nur Aa’in Mazura; & Awang Khairulanwar, published by the Malaysian Journal of Soil Science Vol. 11 : 57 – 69 (2007) – Appendix 12).
Tests on traditional medicines conducted by the National Pharmaceutical Control Bureau between the period of 1993 to 1995, indicated that of the overall data analysis of samples carried out, 11.6 per cent failed to comply with the limit test for lead, that is not more than 10 parts per million.
A team of Malaysian scientists recently examined the lead content of Malaysian herbal supplements and found that some Malaysian tongkat ali products have such a high lead content that even on the Malaysian market, their sale is actually violating the law. The lead content of a good number Malaysian tongkat ali products has been found to range from 10.64 to 20.72 ppm (parts per million).
For comparison, the Indonesian company Sumatra Pasak Bumi has published laboratory test results showing that their own tongkat ali has a lead content of just 0.08 ppm. This means that every gram of the Malaysian tongkat ali named in the abstract of the scientific study contains more than 100 times, and, in some cases, more than 250 times the amount of lead that is found in Indonesian tongkat ali (“Heavy Metals in Malaysian Tongkat Ali” by Serge Kreutz, published by TestingTongkatAli.com, July 2009 – Appendix 13).
Environmental and occupational health experts at the University of Cincinnati (UC) have found that major countries including India, China and Malaysia still produce and sell consumer paints with dangerously high lead levels. The researchers say that this lead-based paint production poses a global health threat, and a worldwide ban is urgently needed to avoid future public health problems.
The research team found that more than 75 percent of the consumer paint tested from countries without controls including India, Malaysia and China had levels exceeding U.S. regulations. About 50 percent of the paint sold in China, India and Malaysia—none of which appear to have regulations on lead—had lead levels 30 times higher than U.S. regulations. Lead-based paints have already poisoned millions of children in the United States and will likely cause similar damage in the future as paint use increases in Asian countries and elsewhere.
The findings provide stark evidence of the urgent need for an effective worldwide ban on the use of lead-based paint (“Study Supports ‘Urgent’ Need for Worldwide Ban on Lead-Based Paint”, published by the University of Cincinnati’s Academic Health Center, 17 June 2006 – Appendix 14).
Globally there is a huge epidemic in terms of lead poisoning and it involves 120 million people who are overexposed to lead, according to the World Health Organization. That is about 3 times the number of people infected by HIV. Some of this lead is coming from these batteries.
It is also known as the silent epidemic because many of the symptoms of lead poison are similar to other kinds of illness, such as the flu. It often gets misdiagnosed until it is too late. Part of our problem is getting the awareness level out there. It is a huge problem, yet it does not get the attention that it deserves.
TO BE CONTINUE….
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