Children pay for riches of Sierra Madre

TOXIC LEVELS of lead have been found in the blood of more than a thousand Mexican children who live downwind of a huge silver and lead refinery in Torreon, 500 miles north-west of Mexico City.

Sulphur dioxide, a by- product of silver refining, stillbelches from the smelter's chimneys and provokes sore throats and headaches but the cause of the widespread blood poisoning is more insidious. Over 120 tons of lead-tainted dust has been scoured from the town's streets and houses by technicians over the past six weeks, as government health authorities took action.

Clad in protective gear and wielding suction hoses, thetechnicians have been nicknamed "ghostbusters" by the vulnerable youngsters who continue to play in the dusty lanes.

Once the stricken children complete hospital treatment, the immediate family must move their households away from the source of the poison without delay, or risk further damage to weakened neurological systems. Lead poisoning was first confirmed in Torreon's children six months ago, but authorities have been slow to act.

Mexico is a leader in silver production with one sixth of the world's total output and a troublesome by-product of an imperfect refining process is lead particles. Penoles, the plant's owner, has been ordered to halve lead production at Torreon, one of the biggest smelters in Latin America, until lead levels fall significantly. That has already badly affected more than 120 mines in the Sierra Madre, and the company intends to step up production again next month if it can meet the health requirements.

Rather than build a new smelter at a crippling cost, Penoles promised to foot the bill for a thorough clean-up of Torreon and to buy up all the contaminated homes for demolition. Relocating its poisoned neighbours across town is a priority. Th company must also cut emissions of dangerous gases and pollutants and pay compensation to victims' families.

Medical treatment of the 400 families who live in the breeze-block houses closest to the Penoles plant is already under way. More than 200 children will need hospital treatment to cleanse the lead from their bloodstreams, yet less than one-third have started therapy.

Entire families sometimes occupy wards together. Onewoman tends the hospital beds of her six-year-old daughter, a hyperactive toddler son, and infant twins who should have been identical, except one was born hydrocephalic. Low levels of lead can cross the placenta and cause birth defects.

Almost one-quarter of the Torreon youngsters register four times the initial danger level of 10 milligrams of lead per decilitre of blood and only these cases have been singled out for medical care. Yet more than 90 per cent of the 1,246 neighbourhood residents initially tested showed confirmed signs of blood contamination with lead.

The symptoms of lead poisoning are varied, depending on the amount in the bloodstream and the length of exposure. Too much can be fatal. Young children often display hyperactivity, learning problems or stunted growth.Nervous system lesions and impaired hearing are common side-effects. Over time, lead poisoning can lead to joint pain, high blood pressure or nervous system disorders, as well as to difficulties in digestion and reproduction. Loss of memory or concentration is typical.

"Our city is not dangerous to live in yet," insisted Torreon's mayor, Jorge Zemeno, "The problem of contamination from the Penoles plant is real but can be remedied."

He pointed to high lead levels in other Mexican towns, which were caused by long-term use of traditional lead-glazed pottery and thus more difficult to tackle. Last year, a march by the concerned mothers of 80 lead-poisoned schoolchildren who had been treated by private physicians in Torreon drew national attention to the city's plight, although a local medical student wrote a thesis about the problem back in 1981. The effects of pollution on plant employees have caused considerable concern over the years at Penoles. After complaints about air quality in 1992, sulphur dioxide levels at the plant were continuously monitored. Unfortunately, the less obvious lead particles were not, nor were the residents who breathe the same vile air.