Reviewed: Ana Maria Pacheco, National Gallery London until January 9th

2000 Blue Suburban Skies, Photographers' Gallery London, until November 20th

Damian Loeb, White Cube, London until November 20th

Ana Maria Pacheco's larger-than-life polychromed wood sculptures were the visual arts highlight of this year's Kilkenny Arts Week, strikingly installed as tableaux in an adapted factory space. She herself was unable to travel to Kilkenny because, with her assistants, she was labouring away on an enormously ambitious exhibition that marks the culmination of her residency at London's National Gallery. The fourth person invited to be an associate artist there (from 1997 until the end of this year), she has come up with a formidable body of work in response to various pieces in the collection.

The main work in her show is a contemporary take on the martyrdom of Saint Sebastian. This multi-figure, polychromed wood sculptural installation occupies an entire large, darkened room and, disconcertingly, visitors can wander right through it, which adds considerably to the eerily life-like impact of her figures. A form glimpsed out of the corner of your eye, which you assume is part of the display, suddenly moves towards you, and your heart skips a beat.

Brazilian by birth, Pacheco mingles references to present-day death squads with the conventional iconography of the saint's demise. A hooded, otherwise naked figure, he kneels on the ground, bound to a post, riddled with arrows, surrounded by sinister laughing men in capes or trench coats, while a crowd of onlookers, young and old, observe proceedings with varying degrees of curiosity, concern and downright indifference.

In fact, one of the strongest groupings of figures is more concerned with an incipient row brewing between two men, whose attitudes of aggression are observed with remarkable precision. There is an exaggerated realism to Pacheco's work that verges on grotesque caricature - typified in the rows of incisors that glint in the open, grinning mouths. Brazilian folk art is an important stylistic influence, but the air of everyday atrocity with which she imbues the story of Saint Sebastian, though it clearly alludes to occurrences in various Latin and South American countries, is universally applicable.

Her victims and onlookers are usually the hapless inhabitants of a Kafkaesque world, in which an inscrutable, malign bureaucracy preys indiscriminately on the innocent and the guilty, the rich and the poor alike.

Pacheco has been criticised on the grounds that the mere depiction of atrocity is not enough in itself. But it could well be that the really chilling thing about her interpretation of the martyrdom is the helpless indifference of the witnesses, who know it is utterly beyond their capacity to influence what is happening, and have given up caring. In any case it is a startling work, backed up by some outstanding ancillary sculptures, prints and paintings, and it is something that must be experienced in the round.

This is the final week for two London exhibitions that, in their different ways, have a certain local relevance. As the expansion of the suburbs enters an explosive phase in the Ireland of the Celtic Tiger, the Photographers' Gallery offers a timely exploration of the subject in Blue Suburban Skies, an uneven but engrossing show, the idea behind which could and should be taken up in some form here.

For example, one of the best exhibits, by German-born photographer Michael Danner, records in a meticulous, forensic way the development of new suburban housing estates, brilliantly capturing the way the distinctive suburban landscape is literally written over the existing rural landscape: something that is happening here all the time. Danner doesn't editorialise, but his images nudge us towards questioning the nature of the built environments we create.

Not that the show is necessarily antagonistic towards the suburban ideal, which was utopian in conception and, some would argue, in effect. Several exhibitors investigate ideas of suburbia, like Bridget Smith, who photographs the rudimentary sets of typical suburban spaces built for "glamour studios", as backdrops for films. Matthew Crawley takes suburban occupations, like DIY, to absurd extremes, as in the engaging Turning on a video camera, opening it up and poking around in there until it breaks, while the machine in question relays a view of standard suburban interior.

Nathan Coley juxtaposes an architectural history commentary on a classic Modernist building with slide views of an anonymous, thoroughly unremarkable suburban villa. It's fascinating to see Dan Graham's slides of an encyclopaedic selection of utilitarian American housing projects, which formed his first exhibition in 1966.

Mary Burke is one of the very few Irish artists who have chosen to depict suburbia in any kind of systematic way.

Equally relevant locally, Martin Gale is one of the few artists to have addressed the actual, rather than the idealised, romanticised or uninhabited rural environment in a sustained manner (Blaise Smith is a younger exemplar). Gale's work particularly comes to mind in relation to the young American painter Damian Loeb, from Mary Boone's stable, whose exhibition Mangoes is currently showing at the White Cube.

Loeb's harshly realist style is blatantly indebted to photography and film. His pictures set up narrative situations, often with sexual overtones, that they don't explain but which, on the other hand, don't require any great degree of interpretation, because we're fairly familiar with every element they contain, having seen the films. Loeb is being promoted as a hot young artist, so it's interesting to note that Gale is a directly comparable and probably better painter, whose work has a much richer density of content and resonance.