UN Enviroment Programme

Chapter 9. Status of soil pollution in Latin America and the Caribbean

Main health problems associated with pollution

In Latin America and the Caribbean, official reports on health problems associated with pollution are mainly prepared by governments in association with international organizations in the field of health, such as the World Health Organization (WHO) and the Pan American Health Organization (PAHO). PAHO has the Environmental and Occupational Health Programme, which provides technical cooperation in environmental and occupational health and consumer protection. WHO (2019) indicated that premature death and disease can be prevented through developing healthier environments. It reported that 23 percent of global deaths (and 26 percent of deaths in children under five years of age) were due to modifiable environmental factors. The PAHO study made by Prüss-Ustün et al. (2016) showed that the diseases with the greatest environmental influence were cardiovascular diseases, diarrheal diseases and lower respiratory infections. Ambient and household air pollution, as well as water, sanitation and hygiene are the main environmental drivers of those diseases. Data indicated that cancers, ischemic heart disease and chronic obstructive pulmonary disease are the diseases that affect the largest proportion of the population.

In the case of health issues related to soil pollution, Prüss-Ustün et al. (2016) indicated that 58 percent of diarrheal diseases are caused by oral faecal pathogens from sewage systems lacking sewage treatment plants, which can then contaminate surface and groundwater. Human excreta can also directly contaminate soil and surface water. The same study indicated that intestinal nematode infections are due to sanitation problems through soil polluted with human excreta containing infectious eggs or larvae. This includes the use of wastewater and excreta in agriculture without adequate risk management measures (WHO, 2006). The practice of wastewater use in agriculture is increasingly contributing to the transmission of soil-transmitted helminths among agricultural workers, communities practicing this form of agriculture and consumers of the resulting products. Transmission of the roundworms Ascaris lumbricoides and Trichuris trichiura occurs when unpeeled food products are contaminated with soil containing worm eggs or grown using excreta or wastewater. Based on an understanding of transmission pathways, all soil-transmitted helminth infections can be attributed to manageable environmental conditions, and are therefore preventable (Prüss-Ustün et al., 2016). Infections with trematodes, such as flukes, are amplified by farm workers in irrigated agricultural production systems, as well as by people living close to irrigation areas and man-made reservoirs (Steinmann et al., 2006).

The Environmental and Occupational Health Programme of PAHO includes a toxicology sub-programme. The aim of this sub-programme is to support the sound management of chemical substances by providing information on their effects on health and the environment, physicochemical properties and toxicological distribution, routes of exposures, preventive measures, diagnostic methods and treatment of intoxicants substances (PAHO, 2019). As part of PAHO’s toxicology sub-programme, a Caribbean health sector was established in 2016 for the Implementation of the Minamata Convention. This focused on issues of dental amalgam; analytical aspects; health aspects: fish consumption; and artisanal and small-scale gold mining.

According to Riojas-Rodriguez et al. (2013), research on environmental influences on children’s health in Latin America is scarce and with 75 percent of papers concentrated on Mexico and Brazil. The aims of the studies were to establish biological monitoring, identify sources of exposure to environmental contaminants and determine potential damage to health. Studies on risk management or population-based interventions to reduce health damage were practically non-existent. These studies often focused on lead, air pollutants, pesticides, and, to a lesser extent, arsenic and mercury. The main obstacles to studies on environmental impacts on health are the lack of certified laboratories and the limited infrastructure to determine the various contaminants and process the required number of samples. In addition, there are insufficient appropriately-qualified professionals with the skills to bridge the gaps between the generation of new evidence and decision-making, including the formulation and evaluation of public policies that benefit children’s health.

9.4.1. Health problems associated with soil pollution in the Caribbean

The Ministry of Health and Environment of Antigua and Barbuda has a Monitoring, Evaluating & Data Management Unit that is responsible for meeting the country’s national, regional and international obligations in relation to environmental health. The public is able to report environmental issues and their impacts on environmental health. In addition, the Management Unit has thematic areas of environmental conditions and environmental quality, with a specialization on soil characterization and soil quality (Ministry of Health & the Environment, 2017). Unfortunately, the data is not available to the public.

In Cuba, the National Statistics and Information Office (ONEI) collects information on environmental and public health issues (ONEI, 2019).

In Jamaica, a study of blood lead levels in 1 081 primary school children found a range of 1.4 μg/dL to 202 μg/dL (Gerald, Bryan and Vutchkov, 2007). Two hundred and thirty children were identified with blood lead levels above 10 μg/dL (WHO threshold level) and of these, 80 received medical attention. The highest blood lead values were found mainly in children from poorer areas of the urban Kingston and St. Andrew Corporate Area, and in St. Catherine. The most important source of lead pollution was its recovery from old automobile batteries and refining in a small smelter that was polluting a significant area. Other studies in Jamaica have found high levels of lead in children’s blood as well as in soil and water samples taken in the vicinity of the study areas (Anglin-Brown et al., 1996; Anglin-Brown, Armour-Brown and Lalor, 1995; Lowe et al., 2002). In a study on the effects of dust emitted by the Caribbean Cement Company Limited (Carib Cement), it was found that the dust emissions covered the surrounding soils with a layer enriched in cadmium, chromium, lead, mercury, vanadium, and zinc, with maximum concentrations at a distance of 3 to 5 km from the cement factory and posed a risk to the health of the population (Mandal and Voutchkov, 2011).

In 2007, the United Nations carried out a chlordecone risk management evaluation, which indicated that the pesticide was used in Martinique and Guadalupe after hurricanes in 1979 and 1980, causing considerable pollution (Multigner et al., 2016). It was estimated that 95 percent of the population of Guadeloupe and 92 percent of Martinique were affected by this POP, causing high rates of cancer among their populations (Vincent, 2018).

At a public hearing in the Dominican Republic, in 2015, the Latin American Observatory for Environmental Conflicts requested the Ministry of Health to investigate contamination from a gold mining operation. In addition, the Observatory demanded the publication of a public health survey conducted in 2013 on the population affected by the contamination. It is an example of community action on soil pollution (OLCA, 2015). This is a very good example of the increasing public demand for access to environmental and health-related data and the need to publish health results related to soil contamination.

9.4.2. Health problems associated with soil pollution in Central America

In Belize City, a study on lead distribution and soil pollution from roadsides, houses, playgrounds and schools revealed high levels of lead in schoolyards and playground soils, particularly in the southern part of the city, resulting from paint chipping or road dust. Environmental exposure over time can have serious health effects (Reeder and Shapiro, 2003).

DDT was extensively used in Belize to combat malaria until 1997. Subsequently a study of soil in two towns in southern Belize, Dangriga and Punta Gorda, showed that DDT had transferred to soils where it persisted for more than 10 years after its ban. Although 24 tonnes of DDT stockpiles were transported to France for elimination (Amandala Newspaper, 2017), soils are still affected and not yet assessed for contaminant levels and health risks (GEF, 2013). It is important to conduct a risk analysis to ascertain whether the concentrations of DDT in these areas pose a risk to the inhabitants of the towns (Somerville and Liebens, 2011).

Costa Rica reported that it faced six key the environmental challenges that have an impact on people’s health (IDB, 2018b). The six environmental weaknesses and threats were: inadequate waste management; exposure and vulnerability to climatic events; lack of water; congestion and pollution generated by public transport; inadequate sewage treatment; and excessive use of agrochemicals. The relative scarcity of water and its pollution are of concern as it can have severe public health implications. Mismanagement of wastewater and poor regulation of productive activities, especially in agriculture, are significant sources of soil and water pollution. Poor wastewater treatment triggers public health problems, such as diarrhoea, and even in some cases can even lead to death. Furthermore, leachate and run-off from polluted soil and poorly managed waste disposal sites are a source of water pollution.

Briceño (2016) indicates that in Honduras, pesticides have a significant adverse impact on public health due to the limited resources available to the government to legislate and monitor the use of these substances. The Ministry of Health has estimated that from 2000 to 2012 the rate of acute pesticide poisoning has increased from 5.8 to 8.8 cases per 100 000 inhabitants, with a case-fatality rate of 12.3 percent, while cases attributable to chronic exposure have not yet been reported. Another study was conducted in Honduras on environmental exposure to pesticides after Hurricane Mitch in 1998, showed significant soil pollution in Istoca (Balluz et al., 2001). The levels of chlorpyrifos and parathion in the soil were respectively 30 and 1 000 times higher than the Environmental Data Quality Level of 0.292 mg/kg soil. In addition, they detected elevated levels of chlorinated and organophosphate pesticides in teenagers. Toxicological analyses showed that 51 percent of the samples had elevated levels of 1,1-dichloro-2,2-bis-(p-chlorophenyl) ethylene (p,p-DDE) and levels of Dieldrin were above 20 μg/dL in 23 percent of serum samples (Balluz et al., 2001).

The Annual Statistics Bulletin by the Health Ministry of Panama for 2017 indicated that the main cause of death was cancer, followed by cerebrovascular diseases, and ischemic heart diseases, with a major incidence among elder people and children under 1 year old (Ministerio de Salud - República de Panamá, 2017). The Ministry also paid special attention to pneumonia, diarrhoea and dene, diseases related soil pollution. It is important to note that Panama is one of the few countries to have made its statistics public; unfortunately, the bulletin has not established a correlation between these diseases and possible environmental causes.

The National Institute of Public Health of Mexico estimated that environmental factors are responsible for 25 percent to 33 percent of the national disease burden, primarily affecting the population under five years of age (INSP, 2019).

Riojas-Rodriguez et al. (2013) indicated that in the city of Torreon, the largest non-ferrous metallurgical complex in Latin America, very high levels of lead exposure have been documented in the local population. Studies have shown that more than 95 percent of children residing in the area had blood lead levels above the internationally accepted threshold value of 10 µg/dL, indicating lead poisoning.

9.4.3. Health problems associated with soil pollution in South America

Peru’s National Policy of Environmental Health 2011-2020 aims to strengthen the prevention and control of health and environmental risks (Ministry of Health, 2011). The majority of the Peruvian population lives in urban areas, where water supply and sanitation systems are inadequate. The policy includes a sanitary surveillance system of environmental health alerts, which allows the identification of environmental risks that have an impact on citizen’s health. The policy also aimed to strengthen environmental health and establish a set of mechanisms and plans to improve responses to emergencies and disasters of environmental health interventions. Zolezzi (2017) indicated that diseases caused by chemical contaminants are an emerging problem in Peru. A common characteristic of these diseases is that their effects on health are not immediate. Establishing causal relationships between soil pollution and degenerative diseases is complex and uncertain.

In Uruguay, Burger and Pose Román (2010) documented a case of health effects related to soil contamination in the industrial district of La Treja in Montevideo. The district had a long industrial history of tanning, metallurgy, battery recycling and oil refining. After the relocation of these industrial facilities, the area became a residential neighbourhood with very little basic sanitation. In 2000, a single case of lead poisoning was detected in a child, which led to an epidemiological analysis. The study revealed that 58 percent of blood samples taken from children under 15 years of age and pregnant women showed values above the established limit. It was decided to relocate families, launch an education programme on the subject, and eliminate lead from many products. The country also developed legislation and protocols for the systematic collection and analysis of environmental samples including air, wastewater and soil.

Mercury levels above the WHO limit and other trace elements were found throughout the small-scale gold mining areas of Guianas region - French Guiana, Guyana, and Suriname (Legg, Ouboter and Wright, 2015). Soil pollution is widespread in those areas, showing heterogeneous mercury concentrations associated to soil erosion and removal of topsoil, with concentrations ranging from 0.09 to 9.22 μg/g in the mining areas, and up to 0.32 μg/g ± 0.18 in forest soils. In their review, Legg, Ouboter and Wright (2015) indicated that populations in small-scale mining areas in these three countries were mainly exposed to mercury through inhalation and consumption of contaminated fish, although indigenous populations not associated with mining activities also showed high levels of mercury in hair samples in some of the regions. Neurological deficiencies and reduced cognitive functions were observed in indigenous children from the Upper Maroni, the Brazilian Amazon basin and French Guiana.

García, Luizaga and Herbas (2016) studied the environmental risk in the Plurinational State of Bolivia, caused by the production and refining of oil generated by the Gualberto Villarroel YPFB refinery, in the vicinity of District 8 (southern zone of Cochabamba). The objective of the study was to propose corrective measures and to understand the local population’s perception of the impact on their health and the environment. The results showed concentrations of total petroleum hydrocarbons (TPH) above the permissible limits of Bolivian environmental regulations. They recommended adapting aeration and land farming techniques to minimize TPH in soils, as well as phytoremediation systems in water channels. In addition, Escobari and Malky (2005) and Effen (2010) indicated that in urban centres near the mines of Oruro and Huanuni in the Plurinational State of Bolivia, acidic drainage has deteriorated pipes resulting in the contamination of drinking water. This had led to negative effects on the health of the inhabitants of these areas as well as premature mortality, reducing the average life expectancy in Huanuni to only 40 years. In addition, there is evidence that the trace elements silver, lead and tin from mining pollution caused neurotoxicity in children aged six to eight years living in San José de Oruro.

The Colombian National Institute of Health (INS) identified the main environmental risk factors that cause illness and death in the country, namely poor water quality, air quality and pollution from solid fuels and trace elements. The technical director of the National Health Observatory indicated that 8 percent of the total deaths recorded in Colombia in 2016 were attributed to environmental risk factors (INS, 2019). Additionally, the Columbian INS’s assessment of environmental influences on health, Quarter III-2018, categorized each reported health impact by it source. It reported the main environmental sources were: 16.5 percent from soil (solid waste disposal, soil pollution by oil spill, soil pollution from mine tailings landslides, and oil exploitation and fracking); 12.7 percent from water; 12 percent from air; and 5.7 percent from water and soil (oil spill soil-water pollution, avalanche/dam failure, and water shortages) (INS, 2018).

In Ecuador, the Ecuadorian Ministry of Public Health, together with academia and civil society, analysed the factors that increase the risk of contracting and dying from cancer. They identified the main potential causes as: alcohol and tobacco consumption, obesity, sedentary lifestyle, certain infections and environmental pollution (Ministerio de Salud Pública, 2019). The results have not yet been released.

The accident of the Samarco Company in 2015 is considered to be the biggest environmental accident that occurred in the history of Brazil (Carmo et al., 2017). The rupture of the tailings dam that contained the toxic waste of the mineral extraction company in the municipality of Mariana (Figure 14) caused the dispersion of toxic waste over 800 km of the Doce River, reaching the Atlantic Ocean, and affected the lives of millions of people and the environment.

Figure 14. The collapse of the tailings dam belonging to Samarco, caused a flood of mud to inundate several houses in the Bento Rodrigues district of Mariana, in the central region of Minas Gerais. ©Senado Federal (via Wikimedia Commons, CC BY 2.0).

The study conducted by Carvalho, Tavares and Lins (2018) in the city of Santo Amaro, Brazil, interviewed 208 randomly selected residents about the risks associated with smelter dross from a nearby lead smelter. Smelter dross containing high concentrations of lead, cadmium, arsenic, zinc, nickel and antimony was given to local population for paving backyards, schoolyards, gardens and other public spaces. The study reported that 97 percent of the soils analysed did not meet the soil quality reference values, according to the Brazilian guidelines for soil quality; 27 sites required preventive measures, such as monitoring, and 11 required intervention. Smelter dross is still widespread throughout the city and its health impacts have been observed in children and adults in at least 56 of the households studied.