Occupational exposure to hydrogen cyanide during large-scale cassava processing, in Alagoas State, Brazil

Abstract

The cassava roots used for flour production contain high amounts of cyanogenic glycosides and are, therefore, potential hydrogen cyanide (HCN) releasers. This fact is the cause of an increasing health concern in the sector of cassava processing. Brazilian workers engaged in the flour production may be chronically exposed to HCN in levels above the safety limits. This hypothesis is based on the drastic reduction in cyanide content of cassava roots during a traditional Brazilian method of processing and in the physical properties of the compound, which makes it very susceptible to volatilization and air contamination. As an attempt to explore this issue, HCN exposure in Brazilian “flour houses” was evaluated in this study through environmental and biological monitoring. Four flour houses placed in Alagoas State, Brazil, were investigated. The results indicated that the cassava processors are chronically exposed to HCN at average levels between 0.464 and 3.328mg/m3 (TWA), in the work environment. This range is below the TLV-C of 5mg/m3 but not below the Action Level of 2.5mg/m3. These data may be interpreted as a possible risk to susceptible individuals. Additionally, the biological monitoring indicated a high cyanide exposure in the population study, considering urinary thiocyanate (SCN-) levels.

Tetrapleura Tetraptera Fruit Protects Against Cyanide Induced Toxicity in Rats

“…Cyanide is a very poisonous chemical and study indicates that sub lethal dose induces signs of toxicity [2]. Presently, there is no food and drug approved antidote that is specifically used for oral cyanide poisoning.…”

“…[1] Certain bacteria and fungi also synthesize cyanide naturally as a component of cyanogenic glycosides to provide a source of nitrogen and for self-defence making this poisonous substance ubiquitous. [2] Cyanide is also as a common environmental pollutant associated with several adverse health consequences such as carcinogenesis, hepatotoxicity, renal impairment as well as disruption of normal endocrine and reproductive functions [2] Most importantly, cyanide occurs naturally as glycosides in over 2000 plants [2,3,4] and ingestion of such plants has been reported to cause acute cyanide toxicity and mortality of live stocks as well as humans [2]. Also, as a result of the increasing use of cassava in particular, in the compounding of animal feeds as a carbohydrate substitute, there is a greater exposure to dietary toxins from cyanogenic glycosides [2,3].…”

“…[2] Cyanide is also as a common environmental pollutant associated with several adverse health consequences such as carcinogenesis, hepatotoxicity, renal impairment as well as disruption of normal endocrine and reproductive functions [2] Most importantly, cyanide occurs naturally as glycosides in over 2000 plants [2,3,4] and ingestion of such plants has been reported to cause acute cyanide toxicity and mortality of live stocks as well as humans [2]. Also, as a result of the increasing use of cassava in particular, in the compounding of animal feeds as a carbohydrate substitute, there is a greater exposure to dietary toxins from cyanogenic glycosides [2,3]. Toxic effect of cyanide is attributed mainly to the production of anoxia following inhibition of cytochrome oxidase, a terminal mitochondrial respiratory chain enzyme [4].…”

Production Methods and Physicochemical Characteristics of Cassava Inoculum and Attiéké from Southern Côte d’Ivoire

“…However, these steps help eliminating cyanide. Zacarias, Esteban, Rodrigues, & de Souza Nascimento (2017) confirm fears and possible exposure to cyanide may be predicted. Heuberger (2005) support these results suggesting cyanide compounds less than 10 mg/kg may be considered safe for consumption.…”

Assessment of cyanide intake through consumption of cassava‐based diets in the Democratic Republic of Congo

“…Cyanide intoxication is caused in most cases by ugali consumption obtained from cassava flour 22 which requires 3, 4, or more days for processing (with sun drying and fermentation method) to remove the cyanide up to recommended level. While cassava leaves, processing is done in a single day with the stages of processing like harvesting, precooking, pounding, and boiling without covering.…”