[PDF Page 1 of 144] Study of Blood Lead Levels of the Population in La Oroya

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1 [PDF Page 1 of 144] Study of Blood Lead Levels of the Population in La Oroya

2 [PDF Page 13 of 144] 1.3 BIOLOGICAL EFFECTS OF LEAD IN CHILDREN Studies and research have determined that lead can have toxic effects on human health, given sufficient exposure to and absorption of it, especially in children, because of their greater sensitivity to the neuropathic effects of lead, compared to adults. For this reason, most of the studies that have been done in the world focus on children. In the last two decades, several prospective and cross-sectional studies have established a relationship between lead exposure and certain deficiencies in the development and growth of children. The investigators showed that in the cases studied, at certain lead levels, effects of distinct magnitude were produced, setting out a scale of possible effects (see Annex 2). Some signs and symptoms of these effects manifest as irritability, decreased concentration, hyperactivity, headache, memory loss, and at the extreme of intoxication, encephalopathy (brain damage). However, experience indicates that the effects indicated are not necessarily present in all cases in accordance with lead levels. Apart from the neurotoxic effects produced by lead, other manifestations may occur in other organ systems. For example, high blood lead levels (80 μg/100 ml) can cause anemia, as reported by studies at low geographic altitudes. A study was conducted in England in 1994 to quantify the magnitude of the relationship between the intellectual quotient scale of children 5 years of age or older with their blood lead level. The authors of this work conducted a systematic review of 26 epidemiological studies since They found evidence in these of a small deficit in the IQ scale of children with high lead levels. The authors who conducted the review point out, however, that the real impact of lead on the neuropsychological development of children remains uncertain, due to the inherent limitations of epidemiological observation. That is, the observed association between these two measures does not prove that one causes the other (4). In addition, intelligence quotient (IQ) is influenced by other factors, such as the intelligence quotient of

3 [PDF Page 14 of 144] the father and of the mother, education received, socioeconomic status, illnesses suffered, state of nutrition, family integration, and circumstances of birth. These factors have many times not been considered in some of the studies carried out to determine the relationship between IQ and blood lead levels in children. In La Oroya, although the population has a history of exposure to lead for more than 78 years of operation of the Metallurgical Complex, emissions from the vehicle parking lot, and other sources of exposure, the regional health establishments have no records of caring for the symptomology of damages attributable to lead in children. With respect to the twice yearly evaluations carried out on the 1300 workers occupationally exposed in the Metallurgical Complex for more than 50 years, it has only been determined that workers with high blood lead levels (greater than 60 μg/100 ml) are for the most part asymptomatic; nevertheless, some show certain symptomology, for which they receive treatment according to Industrial Hygiene protocols.

4 [PDF Page 15 of 144] Information and publications related to studies of the effects of lead on human health.- Research studies related to the effects of lead on human health are published in scientific and medical journals, or in specialized editions in different countries. However, the general public of the countries in which such work is conducted, is still confused about the true health risks associated with lead because the information disseminated by government agencies or advocacy groups, communications media (the press, in general) among others, is often partial, disseminated or approached from different points of view, including opposing or distorted views. These concepts are expressed in the publication Lead and Human Health (1997) of the American Council on Science and Health of the United States, in which many studies conducted regarding the effects of lead on human health are reviewed to clarify the dangers of lead toxicity for the reader, and finds that if sufficient exposure and absorption occur, lead can cause serious toxicity in human beings. In our country, studies of effects of the impact of lead on human health have generally been directed to certain sectors of the population or specific activities, having been carried out in isolation, and by different institutions or independent doctors, and whose publications have had limited diffusion. There have been some studies in La Oroya, including Study of blood lead in a selected population of La Oroya, conducted in November 1999 by the General Office of Environmental Health of the Ministry of Health (Digesa), which included a student population of 346 children between 3 and 10 years old and 199 who were 10 years old and older, and Evaluation of lead levels and exposure factors in pregnant women and children under 3 years old in the City of La Oroya prepared in December 1999 by the Union for Sustainable Development Consortium (UNES). Also, due to poverty and low levels of child health in our country, children suffer from malnutrition, infectious diseases (tuberculosis, meningitis), poor care of home births, etc., ailments and deficiencies that can cause harm to the nervous systems of children, with signs and symptoms similar to those attributed to lead, that impede their differentiation, therefore, it is necessary that a state institution, which could be Digesa, promote implementation of comprehensive epidemiological studies on the effects of lead in children, centralizing existing information from studies that have been carried out, to make a diagnosis of the reality of our country s population with respect to lead exposure.

5 [Section PDF Page 23 of 144] Taking blood samples Of the 6,020 participants in the educational sessions, samples were taken from 5,062 people. Adults agreed voluntarily and children with the consent of their parents or guardians. Blood samples were obtained by venipuncture, and were overseen by Nursing and Clinical Laboratory personnel of the Chulec General Hospital, following the protocol established by the National Institute for Occupational Safety and Health of the United States (see Annex 3).