Chemical-specific health consultation for chromated copper arsenate chemical mixture: port of Djibouti

Abstract

The Agency for Toxic Substances and Disease Registry (ATSDR) prepared this health consultation to provide support for assessing the public health implications of hazardous chemical exposure, primarily through drinking water, related to releases of chromated copper arsenate (CCA) in the port of Djibouti. CCA from a shipment, apparently intended for treating electric poles, is leaking into the soil in the port area. CCA is a pesticide used to protect wood against decay-causing organisms. This mixture commonly contains chromium(VI) (hexavalent chromium) as chromic acid, arsenic(V) (pentavalent arsenic) as arsenic pentoxide and copper (II) (divalent copper) as cupric oxide, often in an aqueous solution or concentrate. Experimental studies of the fate of CCA in soil and monitoring studies of wood-preserving sites where CCA was spilled on the soil indicate that the chromium(VI), arsenic and copper components of CCA can leach from soil into groundwater and surface water. In addition, at CCA wood-preserving sites, substantial concentrations of chromium(VI), arsenic and copper remained in the soil and were leachable into water four years after the use of CCA was discontinued, suggesting prolonged persistence in soil, with continued potential for leaching. The degree of leaching depended on soil composition and the extent of soil contamination with CCA. In general, leaching was highest for chromium(VI), intermediate for arsenic and lowest for copper. Thus, the potential for contamination of sources of drinking water exists. Although arsenic that is leached from CCA-contaminated soil into surface water may accumulate in the tissues of fish and shellfish, most of the arsenic in these animals will be in a form (often called fish arsenic) that is less harmful. Copper, which leaches less readily than the other components, can accumulate in tissues of mussels and oysters. Chromium is not likely to accumulate in the tissues of fish and shellfish. Limited studies of air concentrations during cleanup of CCA-contaminated soil at wood- preserving sites showed that air levels of chromium(VI), arsenic and copper were below the occupational standards. Workers directly involved in the repackaging, containment or cleanup of leaking containers of CCA or of soil saturated with CCA, however, may be exposed to high levels of CCA through direct dermal contact, inhalation of aerosols or particulates and inadvertent ingestion. Few studies have been conducted on the health effects of CCA. CCA as a concentrated solution is corrosive to the skin eyes and digestive tract. Studies of workers exposed to CCA in wood-preserving plants have not found adverse health effects in these workers, but the studies involved small numbers of workers and therefore are not definitive. People exposed to very high levels of CCA, from sawing wood that still had liquid CCA in it or from living in a home contaminated with ash containing high levels of chromium(VI), arsenic and copper, experienced serious health effects including nosebleeds, digestive system pain and blee...

Exposure to CCA-treated wood amongst food caterers and residents in informal areas of Cape Town

“…18 The few studies done amongst CCA-exposed workers in a wood-preserving plant reported no adverse health effects amongst workers, but the number of participants was small. 2 As mentioned before, As and Cr are associated with a number of cancer-related and non-cancer-related health effects (Table 4). Health effects resulting from combined exposure to As and Cr may be additive, but there is no evidence of any interaction between these metals.…”

“…Health effects resulting from combined exposure to As and Cr may be additive, but there is no evidence of any interaction between these metals. 2 Interestingly, there was a high prevalence of respiratory, diarrhoeal and skin problems reported amongst participants, which requires more detailed epidemiological investigation; these symptoms might be a result of other environmental exposures in the communities and the self-reports are too crude a measure of these health problems. The self-reports were included in this study merely to provide preliminary evidence of health effects as the aim of the study was to determine the level of exposure of the participants to CCA.…”

“…Exposure to arsenic (As), chromium (Cr) and copper (Cu) from CCA-treated wood can occur through inhalation of fumes and dust released on combustion of the wood, through contact with the wood ash, or contaminated water and soil, or through ingestion of contaminated water, food or soil. 2 The toxic species of Cr is Cr(IV), of As include As(III) and As(V) and of Cu is Cu(II). Intake of high doses of the toxic species of As and Cr are acutely toxic and could be fatal.…”

Heavy Metals and Human Health

“…Consequently, concerns have been raised owing to the high levels of arsenic and chromium concentrations in CCA treated wood, due to the potential human contact in occupational environments and to the ecological exposure (Chou et al, 2007;Zartarian et al, 2006). In this perspective, concerns about the safety of children have prompted more attention.…”

Mineral Contamination from Cemetery Soils: Case Study of Zandfontein Cemetery, South Africa

“…Besides CCA, ammonium copper quaternary (ACQ) and copper boron azole (CBA) are available on the market [11]. Prior to the 1940s, lead compounds were commonly used as colouring agents in paints [12].…”