POPs impact on people’s health

GENERAL INFORMATION

Even minute concentrations of POPs reveal genotoxic, immunotoxic and carcinogenic effects posing real threat to the health of present and future generations. The principle difference of POPs from other pollutants is their capability to remain in the environment for decades and be transferred by food chains (water - weeds – plankton – fish – human being, soil – plant – plant-herbivores – human being). Thus, POPs are accumulated in the tissues of mammals, including man, where their ultimate concentration does not reduce but augment!
 
Most often POPs get in the human being’s organism together with food, in particular, with meat, fish, chicken eggs and milk products. People living or working in close proximity with the POPs sources can receive a considerable dose of POPs while breathing. At that even a negligibly small amount of toxin can provoke an illness.
Research proves that POPs can provoke such illnesses as chloracne, other skin diseases, functional disorders of immune, reproductive, endocrine, nervous systems; cause diabetes, reduction of lactation period in breast-feeding mothers and developmental lagging in children.

For example, dioxins produce a tremendous effect on immune and endocrine systems of man: their permissible daily dose is calculated in picograms, in figures million times less than a gram!
Main illnesses caused by dioxins are chloracne and liver disorders. Chloracne is a severe form of acne, distorting the skin of the face. The disease can persist for years and can be hardly treated.

Other negative effects of dioxins on human health are:

- Neurobehavioral changes and changes of the thyroid functions (thyroid hormones synthesis disorder) in babies fed on breast milk contaminated by POPs;

- Secondary immune deficiency, which can be provoked by POPs getting in human organism even in tiny doses;

- Gonadotoxic, embryotoxic and mutagenic effects (the impact of dioxins at the genetic level has been identified; fathers – Vietnam War veterans – gave birth to a considerable number of children with inborn abnormalities).

- Physical and mental developmental lagging;

- Reduction of lifetime and others.

It is not clear yet whether dioxins definitely cause cancer. The research undertaken in Sweden and Finland proved inconsiderable hazard of cancer at that there are not data on the content of dioxins in the organisms of the workers, i.e. on the absorbed dose.  American scientists who studied the health condition of the veterans of the Vietnam War did not claim higher mortality rates in this group caused by cancer. Further medical investigations in this sphere will give a more definite answer to this question.
  
Pesticides are important for the agriculture but nevertheless they cause various health problems depending on the degree of their impact.

A “cocktail” of pesticides can be regularly found in the food products such as apples, pears, oranges and carrots used for child feeding. Apart from fruit and vegetables pesticide residues are found in other popular products of everyday use. For example, lindane – pesticide destroying hormones – which is banned in Europe, can still be found in chocolate made from cacao imported from the countries of the third world where POPs pesticides have been extensively used in agriculture. In the course of the wide-scale international research in 1998 lindane was found in 12 out of 16 samples of chocolate. Lindane residues have been also revealed in milk, meat, cheese and mushrooms.
Pesticides also pose significant threat to children’s health. Children can be impacted by pesticides everywhere: in cases when their parents use and store pesticides without necessary safety measures; when pesticides are used on the territory of playgrounds, schools, and parks.

DDT is especially dangerous and its effects are not well studied yet. However, for the decade of 1970-1980 the incidence of pesticide poisoning in the world grew by 250 percent. DDT accumulates primarily in adipose tissue in humans as well as in animal species, but this pesticide can be released with breast milk and even penetrate the placental barrier.

DDT impact can cause hormone disorders, affection of kidneys and central and peripheral nervous system, hepatocirrhosis and chronic hepatitis. Regardless of practical absence of genotoxicity, DDT is classified as high carcinogenic hazard. Thus, DDT poses high level threat both to people’s health and the environment.
PCB is the most widely spread persistent organic pollutant. PCBs were produced in great amounts beginning from 1929. Since that time and till 1986 (ban for their industrial production) about 2 million tons of PCBs were produced.

According to the data of WHO the major ways of PCB penetration in the environment are the following:

• Evaporation from plasticizers;
• Emissions from incineration of household and industrial wastes, as well as from combustion of transformers, capacitors and other industrial equipment containing PCBs;
• Releases of with other industrial wastes; PCB storage at dumps and aeration fields;
• Other uncontrollable ways.

The first three are the most likely ways of contamination of the environment with PCBs.

PCBs can accumulate in the organism; impact the endocrine system, change sexual behavior, cause malformations in children, hamper mental development. Female organism is negatively impacted by PCB even before the formation of the embryo when generative cells are damaged.

IMPACT OF POPS ON THE HEALTH OF POPULATION IN THE REPUBLIC OF BELARUS

Assessment of chlororganic pesticides impact

First studies to identify the daily permissible does of chlororganic pesticides in the human organism were undertaken by the specialists of Belarusian Research Institute of Sanitation and Hygiene in 1974-1975. These studies proved that the main input to the formation of the daily does made milk and dairy products, meat and meat products. The revealed daily dose did not exceed the established international standards.

In 2000-2002 the specialists of the Republican Research Practical Center of Expert Assessment of Quality and Safety of Food Products of the Ministry of Health of Belarus studied the daily diet of pregnant women and breast-feeding mothers and analyzed the content of chlororganic pesticides in the consumed products to calculate an average dose of chlororganic pesticides consumed with the food.

According to the obtained data, the content of the total DDT and its metabolites in the diet of pregnant women and breast-feeding mothers staying in hospitals and maternity homes of Minks and Vitebsk is generally 100 times less than the level of daily permissible does that is 0.005 mg/kg.

When chlororganic pesticides are accumulated in the female organism during lactation period they are released with the breast milk, which poses a real threat of pesticide penetration in the organism of a child during breast feeding. Therefore analysis of the breast milk is an impartial indicator of contamination of the organism with the chlororganic pesticides, and it also helps assess the level of risk for the baby and correct the diet of the mother and the child.

To study contamination levels of the breast milk 84 samples of breast milk of women from Mozyr, 16 samples – from Svetlogorsk, 32 samples – from Soligorsk and 15 samples from Dokshitsy were analyzed. DDT in the form of its metabolite DDE was identified in all samples of breast milk. All samples also contained hexachlorocyclohexane (HCCH). Dependency of release of chlororganic pesticides with milk on the period of lactation is rather complicated but considerable reduction of these chemicals content was not observed in the course of the study (327 days).

Chlororganic pesticides accumulate more as a woman becomes older. Thus, the amount of pesticides released with breast milk is growing. This pattern was registered while samples of breast milk of the women from Minsk and Mozyr were studied.
 
On the basis of the content of chlororganic pesticides in breast milk and baby weight the daily intake of pesticides for a kilogram of baby weight was calculated. Daily intakes of HCCH for babies exceeded permissible levels in Mozyr and Soligrosk – in 5 percent of cases, in Minsk – in 3.2 percent of cases. The same indicators for the total of the DDT metabolites are considerably higher and make 39 percent in Mozyr, 32 percent in Soligorsk, and 48.2 percent in Minsk.

Therefore, the problem of the impact of chlororganic pesticides on human health is still acute despite their use has considerably decreased everywhere. The data on the concentration of chlororganic pesticides in breast milk can be taken as a criterion for the estimation of the associated contamination of food products and as a basis for development of measures to reduce the impact of pesticides on children under one year of age given the impact of other POPs, radionuclides and nitrates reinforcing an adverse impact produced by chlororganic pesticides.

Environmental situation in Belarus in terms of the impact produced by chlororganic pesticides is not critical but it can hardly be assessed as favorable given the data on the concentration of chlororganic pesticides in breast milk and the associated impact on children under one year of age.

Assessment of the impact of dioxins on the health of workers

At present there are no data on the studies related to the assessment of the risk of chlororganic pesticides and PCBs impact on the people working in contact with these chemicals. The use of chlororganic pesticides in the republic is banned (DDT was banned in 1970, HCB has not been used since 1990, toxaphene was banned in 1991, aldrin – in 1972, HCCH was used before 1996, chlordane was used in 1966-1980); therefore it is not feasible to assess their impact on the health of people handling these chemicals.
 
There are only random data related to the assessment of the risk of the workers’ exposure to dioxins; therefore it is rather difficult to make conclusions on the dioxins effect on the health of people who work in direct contact with these substances. First of all, there are no quantitative data on the pollution of the work places with dioxins. Secondly, a long period of observation and biological monitoring is needed, which will prove the relation of contamination of the organism with dioxins and health problems. Thirdly, to make a comprehensive assessment of the impact on health all potential pathological consequences of the contact with dioxins/furans have to be studied.

Prevention and reduction of the negative impact of POPs on health

Prevention measures to reduce POPs impact on health can be divided into two groups: governmental measures and measures that every one of us can undertake having necessary knowledge on the potential sources of POPs and their properties.
Governmental measures for minimization and prevention of the impact of POPs on people’s health include control of contamination of the food products, drinking water and water of rivers and lakes, soil with POPs, as well as monitoring of health of people working in contact with POPs. Such studies are carried out by the state sanitary inspectorates, environmental inspectorates and inspectorates for control of food products.

At present more than 5000 samples of food products and drinking water are analyzed annually for the content of the residues of such pesticides as DDT and its metabolites, aldrin, heptachlor, HCCH. In case pesticides residues exceed permissible levels contaminated food products are removed from the consumer chain and are disposed of. If high concentrations of POPs are revealed in drinking water special protective measures are taken (provision with water from other sources, clean up of the water source, etc.). It is worth mentioning that such cases have not been registered in the republic yet.

Since 2006 the inspectorates of governmental sanitation control have established monitoring of PCB content in fish and fish products, a system of dioxin control in food products is planned to be introduced. Only such studies prove that food products and drinking water from centralized and decentralized water sources do not contain hazardous concentrations of POPs.

Medical examinations help to prevent people working in unfavorable conditions (agricultural workers handling pesticides) from the exposure to POPs and to identify disorders and illnesses related to the working conditions.
  
To protect yourself and your family from the potential impact of POPs it is important to know about the sources of POPs penetration in the organism and take simple preventive measures.

POPs are lipophilic so they accumulate in the tissues containing fat, including some food products. Limited consuming of food products containing a lot of fat (fatty meat, fatty fish), will not only reduce the penetration of POPs and other lipophilic pollutants in the organism but will also reduce the risk of obesity, cardiovascular diseases, and diabetes.

Reduced consumption of “fatty” foods is especially recommended to women planning childbirth and breast-feeding mothers as POPs penetrating breast milk can negatively impact the health of the baby.

It is not recommended to consume fish caught in the ponds situated in proximity with dumps, pesticide landfills and industrial enterprises – potential sources of POPs – and drink water from surface sources.

The use of POPs pesticides was banned more than 20 years ago. However such pesticides can still be found in the stockpiles and in private households. People unaware of the hazard of these chemicals can sell these pesticides to other people. Pesticides legally sold in our country all have certificates proving their safety if used according to the instruction. Therefore it is advisable to check the availability of such certificate when you buy pesticides from other people. But it is safer to buy pesticides in the specialized shops.

It is unsafe to use chemicals that are stored in the unmarked containers.

You may not keep food products and drinking water in the containers that were used for storage of chemicals. Usually such containers are of bright colors (red, yellow, orange) or have bright strips on them.

It is known that dioxins/furans are by-products of incineration, including incineration of polymer materials. Therefore you may not burn polymers (plastic and plastic goods etc.) and use the ashes plastic of painted wood as fertilizer.
 
If you observe these simple rules you will minimize the risk of POPs adverse impact on your health and the health of your children.