Last week, 23 children - some as young as five, none older than 12 - died after eating the free lunch provided at their school in a village in the state of Bihar in northern India. Another two dozen remain hospitalized. They'd reportedly complained about the oddly blackened look of the meal, the bitter taste. But their principal insisted that they finish their food - a dish of beans, potatoes and vegetables - as good children should.

The principal, who had fled, was arrested yesterday. There's no word yet on her husband who also vanished - a grocer who supplied the school kitchen with what now appears to be cooking oil stored in pesticide containers. The obvious skimming of government money provided for school lunches, the charges of engrained corruption and slippery politics, and the absolutely needless deaths of young (and trusting) children has set off a round of accusations and recriminations in India. And also some more deliberate copy-cat poisonings, such as an incident yesterday near the city of Bhopal in which a man dropped rat poison into food being prepared for 50 students at a hostel (who, thankfully, refused to eat it due to the smell).

Lethal pesticides and other poisons are less tightly regulated in India - and many countries in Southeast Asia - than they are here in the United States. The resulting easy access, the easy familiarity, are among the reasons that mass poisonings remain more common there than in our corner. Let's not forget that also, last week, 22 people died after eating a poisoned dinner in Pakistan. The murders were relatedto a feud between two brothers. Those circumstances also play into small scale poisonings that often receive little attention, such as this barely noticed story from June in which a mother killed herself and her three children with poison, or this April incident, meriting a bare three newspaper paragraphs, in which the owner of a private school in Binkaner, India raped two young girls in his care and poisoned them when they threatened to tell.

It's a pattern that allows people to become far too casual in the way they live with, and think of, very poisonous products. Which brings me back to the heartbreaking story of those 23 dead children in Bihar. At a farmed owned by the headmistress, Meena Kumari, police reported that they found empty pesticide containers.

In fact, the very pesticide that killed the children.

The working theory is that her husband used some of those empty containers to store cooking oils and other food products, then sold them to the school at top price.

The other theory is that, like the dinner poisoning in Pakistan, this was deliberate, perhaps an attempt to embarrass the state government. So far, authorities lean toward the idea of callousness and carelessness. Doctors reported finding levels of the pesticide monocrotophos in a concentrate five times higher than the standard formula for commercial pesticide, suggesting that perhaps the family had been mixing up their own formula on the farm. Of course, that concentration could also speak of something more deliberate, another reason why the police are working so hard to find all those responsible.

You may not have heard of monocrotophos; it's been banned in the United States for years. (It's also banned in Argentina, Australia, Brazil, Cambodia, China, the Dominican Republic, the European Union, Indonesia, Iran, Jordan, Kuwait, Laos, Lebanon, Libya, New Zealand, Pakistan, the Philippines, Qatar, Saudi Arabia, South Africa, Sri Lanka, Syria, Thailand, Vietnam and Yemen.) The Pesticide Action Network reports that it was also banned for use on vegetables in India in 2006 due to high residue levels but is "easily available and widely used on them."

Or, as Reuters reported, India seems to have ignored the World Health Organization's warning about monocrotophos - WHO recommends that the pesticide be phased out entirely.

It doesn't take long to figure out why. Monocrotophos - sold under the trade names Hazodrin, Azodrin, Dominator, Plandrin, Megatron, Macabre (personal favorite) and Phoskill among others - has left a trail of damage since it was first registered. It was introduced in the United States in 1965 by the chemical-pharmaceutical giant Ciba-Geigy (now Novartis). It soon was linked to massive bee die-offs and thousands of dead birds, leading the U.S. Environmental Protection Agency to start limiting its use in 1984 and to ban it outright in 1991. The American Bird Conservancy, which lobbied for its withdrawal, calls it "one of the most avian-toxic substances ever developed." The LD50 for golden eagles (lethal dose, 50 percent) at which it is capable of killing half of a given population is a mere .2 milligrams/kilogram of body weight. Monocrotophos caused notable bird kills elsewhere, including an incident in Argentina where 100,000 birds were killed after one heavy application in 1997. And, yes, the pesticide is now banned in that country too.

In humans, it's considered just plain lethal in a dose of 5-50 mg/kg, translating to a killing dose "between 7 drops and 1 teaspoon for an 150-pound adult." Much less for a small child, obviously. It belongs to a class of neurotoxic compounds called organophosphates, which derive from phosphoric acid, and which include both nerve gases and pesticides. Their primary mechanism is to disrupt production of an enzyme (cholinesterase) which is essential to regulating chemical signalling in the nervous system.

Without such regulation, the signals simply go haywire. Symptoms may start with a sensation of anxiety, a creeping headache, a rising nausea and cramps but they spiral rapidly into much worse across a broad scale: convulsions, a stuttering heartbeat, difficulty breathing, paralysis and coma. Monocrotophos also absorbs through the skin and WHO estimates that it plays a major role in tens of thousands of intentional and accidental pesticide deaths in India every year, where it's used on a wide range of crops, including cotton, rice, vegetables such as tomatoes, fruits such as mangoes and grapes, coffee, tea, olives, sugar cane, tobacco, soybeans and cabbage. The website Toxipedia also documents injuries to farmers in other countries - in both Brazil and the Philippines, before the pesticide was banned, health authorities found a consistent pattern of harm to agricultural workers.

For all of those crops, there are many less dangerous alternatives in battling back insects. So why does any country still allow this one?

A 1994 paper from then-Ciba-Geigy highlights some of the reasons. It's "low cost and efficient" and easy to make. Still, the company phased out its production in the year 2000. A few years later the major U.S. manufacturer, Dow Agrichemical, also decided against manufacture of a risky product. With the formula patent now expired, India and China are the primary producers of cheap generic versions (more than 16,000 pounds a year are produced in India alone). And the World Health Organization says monocrotophos, a broad-spectrum killer, tends to be the pesticide of choice for the country's poorest farmers, desperate for inexpensive ways to protect their crops.

WHO also believes that monocrotophos routinely kills people as well as insects. In a 2009 report, the agency points out that organophosphate exposure is linked to depression and increased suicide risk. It notes that the suicide rate among the poor farmers of India has been steadily rising - at the time of the report it was officially more than 17,000 people a year (largely considered an underestimate). Many of those farmers killed themselves by drinking monocrotophos. Between 1997 and 2005, pesticide suicides in India overall topped 190,000 people, enough to clear out a small city.

According to the WHO, India has found it difficult to enforce the 2006 monocrotophos ban for vegetables because it is used on so many crops, especially cotton. The country considered a universal ban but was apparently persuaded otherwise by a discussions (read, suspected bribes) involving pesticide industry representatives. Would such a ban have saved those poor children in Bihar last week? Of course, not. There are countless other poisons to use either mistakenly or deliberately in any country, especially one that keeps the bar low on consumer education and protection.

But the fact that the killing agent was this one, this macabre pesticide outlawed by countries including India's neighbors, speaks to the curious comfort with lethal compounds the country so far maintains. It speaks to an indifference to those without money and power - poor farmers, poor children, birds and animals trapped in the cast of a toxic net. It undoubtedly speaks as well to the charges of corruption and politics that followed the mounting toll of dead children. Because the truth about public education and solidly enforced regulation is that these are tools of equality. They respect the least powerful as well as the most.

There's plenty of resistance in our country today to government regulation, but let's take a moment to appreciate that we banned this very dangerous pesticide more than 20 years ago, protecting our farmers, our children, our wildlife. And to appreciate all the countries, from Cambodia to Australia, that did the same. There's a value in such protective measures that countries like India, seeking to become major economic powers, should take to heart. And there's a value that countries like our own should not forget.

Image: Chemical model of monocrotophos (C7H14NO5P)/Wikipedia