Background Evidence of chronic low levels of exposure to heavy metals in Sri Lanka has emerged in a number of studies carried out in the recent past. The source and magnitude of such exposures have to be understood in order to assess the risk of adverse health effects of this exposure and to propose suitable public health interventions. Methods An assessment was carried out to quantify chronic exposure to cadmium, lead and arsenic through food in people living in an area in Sri Lanka, where prevalence of Chronic Kidney Disease of unknown origin (CKDu) is highest. First a dietary survey was carried out in the subjects to estimate the type and quantity of typical food items in order to estimate an average consumption. A model diet was formulated using this dietary consumption data; and this was thereafter used for estimation of chronic dietary exposure of selected contaminants. In parallel, the levels of contaminants of interest in the various identified food items: cadmium, lead and arsenic, were determined. Results Assuming the major route of intake is food, and based on the quantity and type of food items consumed, a 60 kg man is exposed to average doses of 83.7 μg cadmium, 924.1 μg lead, and 180.3 μg arsenic per week. The impact of chronic lead exposure was affirmed by a mean blood lead level of 3.0 μg/dL, with a maximum level of 8.8 μg/dL being observed in some cases. Conclusions Chronic low dose exposure of lead from food appears to be a public health concern in the studied population. Cadmium exposure through food appears to be of concern also. However, arsenic exposure through food appears to be within safe limits. As there are numbers of possible adverse health outcomes that can be associated with such estimated exposures of heavy metals, public health interventions are warranted to limit the described harmful exposures. Advocacy on dietary patterns and agronomic practices to lower the contaminants identified are the two broad strategies suggested.

Background: This article describes the analysis and interpretation of data relating to the presence of cadmium, lead, mercury and fluoride in human bone samples obtained from cadavers of patients dying of Chronic Kidney Disease of uncertain aetiology (CKDu) in a case-control study, which the authors believe to be the first in Sri Lanka. Methods: This is a case-control study comparing selected nephrotoxins levels in autopsy samples of bones from persons confirmed to have died of CKDu, and who had lived in a CKDu hotspot and controls with no history of abnormal kidney functions who had lived in areas having a low prevalence of CKDu. Results: The average age at death of the cases was 59.6 ± 15.1 (±SD), while that for controls was 58.0 ± 19.3 (±SD) years with no significant statistical difference. Calcium adjusted bone lead and bone fluoride levels were significantly higher among CKDu cases (n = 14) than those of controls (n = 33). Further, younger and older clusters of CKDu cases can be differentiated when the calcium adjusted lead content was considered. Younger patients reported higher lead content compared to the older group. Cadmium and mercury content did not show a remarkable difference among cases and controls. Conclusions: Our results show a significant accumulation of lead in bone tissue in persons who have died of CKDu which indicates a higher chronic exposure of the CKDu victims, to lead. Fluoride content in the bones of cases is also significantly high. The results indicate that a gradual reduction of glomerular filtration rate (GFR) may have occurred with the chronic exposure to lead. At a certain point of the threshold of low GFR, excretion of fluoride may be impaired, since the main excretory pathway of fluoride is via the kidneys. Fluoride accumulation in blood in turn may exacerbate nephrotoxicity, triggering a synergistic cascade of events which may lead to a further deterioration in the GFR. The extremely high fluoride content detected suggests a cumulative effect in people exposed to comparatively higher fluoride levels, most probably from drinking water.

Work-related musculoskeletal pain was much more common than the general health issues reported. Health promotional programs at workplaces focusing ergonomics will benefit the workers at small-scale industries inSri Lanka.

In a recent study published by the National Project Team on chronic kidney diseases of unknown origin in Sri Lanka, identified cadmium as a major risk factor but strong conclusions were not made as the identified environmental toxins were within the permissible levels.Sri Lankan food consumption pattern is different so that approach of total exposure of cadmium by food and water been calculated. Such calculation point out that total exposure of cadmium exceed the provisional tolerable weekly intake determined by international agencies.

Purpose : Evidence of substantial levels of chronic exposure to heavy metals from food has emerged in a number of studies carried out in the recent past. The contamination of rice, the main dietary staple, is attributed in the main source to this chronic toxicity. Determining of source and magnitude of such contamination will assist to propose suitable public health interventions.Research Method : The area with the second highest prevalence of Chronic Kidney Disease of uncertain aetiology (CKDu) in Sri Lanka; Padaviya Divisional Secretariat area paddy fields were selected for the study. Paddy samples were collected from cross-section of locations with GPS locations, intended to represent the entire field. Paddy was processed for rice by routine methods. The fields were rain fed or irrigation fed, this being duly noted. Findings : Analytical results were expressed on a wet matter basis. Mercury was not detected in any of the 196 samples. Out of 196 rice samples, 21 (11%) had no detectable levels of lead or cadmium. Seventeen (9%) samples contained cadmium exceeding 50 μg/kg and lead exceeding 100 μg/kg. The minimum, maximum and mean lead levels in rice were 50, 790, 118 μg/kg respectively. Minimum, maximum and mean cadmium levels in rice were 30, 280, 33 μg/kg respectively. Lead contamination appeared to be an equally widespread issue in the tested irrigation water fed paddy fields. However, determined lead concentrations are significantly lower in rain-fed fields. Cadmium contamination seems to be significantly greater in the rain-fed fields than in irrigation-fed fields.Originality / Value : The magnitude of contamination of potential nephrotoxic heavy metals and its geospatial distribution in rice which is the main staple diet of people living around the studied paddy field where second highest CKDu prevalence were reported, and have been revealed. The information generated can be utilized to reduce the contaminant levels by agronomic practices and diet based public health intervention to reduce the human exposure.