The rapid aging of society has brought about another embarrassing problem ― a sharp increase in sex crimes committed by aged men, which are targeted mainly at children and other vulnerable people.

According to figures from the police, the number of sex offenders aged 61 or older increased by more than 50 percent from 710 in 2008 to 1,070 last year. More than one in 10 child sex crimes in 2011 were committed by people in their 60s or 70s.

In the latest case, a 66-year-old janitor of a primary school in Changwon, South Gyeongsang Province, was arrested this week on suspicion of sexually harassing nine students on 55 occasions over the past year. Several men in their 60s or 70s have been investigated for allegations that they sexually assaulted a mentally handicapped woman for years in the southern coastal town of Tongyeong.

The increase in sex crimes by the elderly comes in parallel with a growing proportion of aged people in the population. More aged men remain sexually active due to relatively good health and medication. A study released by the Health and Welfare Ministry this year showed more than 60 percent of men aged 61 or older still have sex.

In many cases, however, their sexual desire is not matched by their female spouses in the same age group, who follow a different biological curve.

Problems with aged men living alone could be more severe as they are more inclined to commit sex crimes out of frustration at being alienated from society.

With age weakening judgment and restraint in senior people whose sexual ability is intact, they are more likely to be deviant sexually, according to experts.

Our society has not paid serious attention to the sexual life of the elderly and their sex crimes, partly influenced by the traditional attitudes of respecting senior people and ignoring sexual matters involving them.

But sex offenses by aged men should no longer be left without being addressed fully.

Sex crimes by the elderly should be dealt with sternly as they are mostly committed against vulnerable targets including children and physically or mentally handicapped women. Tolerance should not be considered just because the sex offenders are aged people.

In parallel with stern punishment, more effective programs need to be implemented to help activate sexual life among senior partners and help elderly people exercise restraint to avoid being tempted by warped sexual desire.

Measures should also be strengthened to protect children and other people vulnerable to sex crimes by elderly men.