Long-term consequences of arsenic poisoning during infancy due to contaminated milk powder

Abstract

Arsenic toxicity is a global health problem affecting many millions of people. The main source of exposure is drinking water contaminated by natural geological sources. Current risk assessment is based on the recognized carcinogenicity of arsenic, but neurotoxic risks have been overlooked. In 1955, an outbreak of arsenic poisoning occurred among Japanese infants, with more than 100 deaths. The source was contaminated milk powder produced by the Morinaga company. Detailed accounts of the Morinaga dried milk poisoning were published in Japanese only, and an overview of this poisoning incident and its long-term consequences is therefore presented. From analyses available, the arsenic concentration in milk made from the Morinaga milk powder is calculated to be about 4-7 mg/L, corresponding to daily doses slightly above 500 μg/kg body weight. Lower exposures would result from using diluted milk. Clinical poisoning cases occurred after a few weeks of exposure, with a total dose of about 60 mg. This experience provides clear-cut evidence for hazard assessment of the developmental neurotoxicity. At the present time, more than 600 surviving victims, now in their 50s, have been reported to suffer from severe sequelae, such as mental retardation, neurological diseases, and other disabilities. Along with more recent epidemiological studies of children with environmental arsenic exposures, the data amply demonstrate the need to consider neurotoxicity as a key concern in risk assessment of inorganic arsenic exposure.

Cancer excess after arsenic exposure from contaminated milk powder

“…However, the number of patients in Okayama Prefecture is reported to be 2,005, and at least 33,500 one-pound cans were consumed in Okayama [7]. Because the dose of poisoned milk powder needed to cause clinical poisoning in an infant corresponds to five cans [6], the number of possible acute poisonings in Okayama could, therefore, have been three times the official estimate. Because the size of a 5-year birth cohort in Okayama is approximately 150,000, this means that the number of clinically poisoned subjects may represent only 4% of the cohort.…”

“…During early summer in 1955, mass arsenic poisoning of bottle-fed infants occurred in the western part of Japan because of contaminated milk powder [6]. Although the contaminated milk was announced as the cause of the poisoning and ordered to be recalled on August 24th, contamination continued for at least 4 months [7].…”

“…Affected infants manifested skin pigmentation, diarrhea, and fever, and more than one hundred died from acute poisoning [7]. The estimated total dose of arsenic leading to diagnosis was 60 mg [6]. Although subsequent studies demonstrated high incidence of neurological disorders [8] and skin disorders [9] among affected subjects as they reached adolescence or adulthood, a follow-up study of officially recognized patients up to 40 years old did not provide definitive evidence of increased cancer mortality [10].…”

Lead Toxicity: Does the Critical Level of Lead Resulting in Adverse Effects Differ between Adults and Children?

“…Apart from human studies, lead exposure during early stages of the rat brain development has been suggested to decrease protein kinase C (PKC) activities and also to reduce PKC isoforms including PKC-γ and ε which are reported to have roles in memory formation and long-term potentiation 108) . Since early exposure to lead at the developmental stage, as well as to methylmercury and arsenic [109][110][111][112][113] , can produce lifelong loss of intelligence and permanent disruption of behavior 114) , special attention should be directed to food and water safety for younger children and mothers.…”

Effects of corporate social responsibility on food safety

“…The incident became known as the "Morinaga dried milk poisoning". By 2002, there were an estimated 13 400 cases and over 100 deaths attributed to consumption of the milk powder (Dakeishi et al 2006). Incidents related to food security are reported almost every year from all over the world.…”