If we were to look into a crystal ball at the future U.S. population, the picture would look similar to that in California today. California is the leading state of residence [1, 2] for authorized and unauthorized immigrant populations. Demographic experts [3] have projected that by the year 2030 only one third of all children in California will be of European descent.

Figures from the Census Bureau [1] confirm that since 1970 only 2.7% of the 15 million immigrants who came to the United States were European. The proportion of total foreign-born persons from Latin America and Asia increased from less than 1.5% each in 1900 to 43% and 25%, respectively, in 1990. The estimated total undocumented immigrant population residing in the United States was 3.4 million in 1992 and growing at a rate of about 300 000 per year, with Mexico, El Salvador, Guatemala, Canada, Poland, and the Philippines the leading countries of origin [4]. This rapid increase in the proportion of immigrants from Latin America and Asia means that the future of the United States will largely be in the hands of their children. For the United States to survive with health, our society must address the needs of that population now.

What is the health of these new arrivals? Because of the lack of comprehensive published studies about immigrant health and the difficulty in obtaining data from immigrant populations, the answer is elusive. The problems of immigrant populations mirror those of the nations from which they come. For example, the Latin American immigrant population in California [3, 4] has had episodes of tuberculosis, measles, and polio. Tuberculosis, hepatitis B, and measles occur in many Asian-Pacific Islander immigrant groups as well [5-7]. These conditions are easily managed, however, by public health methods often not available in the immigrants' native countries. Increased investment in our public health systems for proper screening, treatment, and follow-up can greatly and cost-effectively improve these conditions.

According to several studies documenting health status indicators, recent immigrants fare better than the U.S.-born population in many health categories. Recent studies [8-10] in Los Angeles County found that Asian and Latin American immigrant populations have lower infant mortality rates and better birth outcomes than the U.S.-born population. According to a Los Angeles County vital statistics report [9], Latin American and Asian populations have much higher life expectancies and lower age-adjusted mortality rates than other major groups. Stephen and colleagues [11] reported that, overall, foreign-born persons have better health than U.S.-born persons, although this health advantage varied by length of residence in the United States. In virtually every measure of health status and with regard to almost every sociodemographic characteristic, the most recent immigrants are healthier than both foreign-born persons who have lived in the United States for 10 years or more and U.S.-born persons.

One resounding feature of the health care system that many immigrants face is the lack of access to care of adequate quality. This lack of access, coupled with wide exposure to unhealthy U.S. lifestyles that are linked to costly chronic conditions [11], is a prescription for disaster, a prophecy already materializing in Los Angeles. The extent to which the health of recent immigrants declines over time reflects their risk for poverty, which, in turn, imposes ominous barriers to adequate health care. Improving access to health care and, in particular, to preventive health care, will substantially improve the health status of all those afflicted by poverty.

But health care has costs. In a recent study [12] completed by Los Angeles County, the net cost to the County for providing health care to immigrants was approximately $350 million per year, with undocumented immigrants accounting for half of the costs. In short, immigrants used more services than were paid for by their contributions in taxes and other revenues to the County. Just as alarming was the discovery that the native-born population also uses more services than they generated in taxes and other revenues, an excess of $200 million [12]. Thus, it appears that immigrants are simply falling into a deficit pattern already prevalent among the poor of Los Angeles County. Given the types of chronic health problems inherent in the United States, the future costs will grow to even more astounding levels.

In discussing the cost of providing health services to immigrants, however, it is important to remember the cost of not providing services. Although this cost can be registered in dollars, it is better reflected in the immeasurable value given to human life. It is an ethical question: Where we choose to allocate our resources determines our destiny. I believe that we must choose to allocate our resources to provide a healthy life for each resident of this country. One of the wisest uses of our resources is increased investment in our public health systems, which better prepares us for promoting health and preventing disease.

However, the option of denying access to health and social services is now surfacing. In November 1994, California voters approved an initiative that denies all public social services to anyone until the legal resident status of the person has been determined. The Save Our State (S.O.S.) Initiative imposes an immense new administrative burden on local governments and agencies and effectively eliminates public education and health care, except for emergencies, unless proof of citizenship or legal residency can be established. In all likelihood, few undocumented immigrants would be compelled to leave the state because of the initiative; they would instead potentially spread disease and remain ignorant of their disease status out of fear of requesting any health care service.

The threat of contagion is real and was shown, in September 1993, in a middle-income area of Southern California where 292 high school students (23% of the student body) had positive test results for tuberculosis. Recently, another 84 students had positive results. An investigation showed that the initial case started with a 16-year-old Vietnamese immigrant who had contracted the disease before immigrating. Even though it is clear that the situation could have been handled better and probably could have been prevented, the threat of contagion should be taken seriously. This case also points out that an alert, properly funded and trained public health infrastructure is critical to safeguarding community health.

California's Governor has also issued a statement intended to eliminate prenatal services for persons who are not legal U.S. citizens or residents. Opponents to the initiative have pointed out that the Governor's view is short-sighted because babies born to illegal immigrants are U.S. citizens. If these babies have health problems that could have been prevented by inexpensive prenatal care, then California taxes will be expended to pay for costlier health care and rehabilitation. To put this in perspective, in 1993 the state Health and Welfare Agency indicated that nearly 300 000 illegal immigrants gave birth. Further, 40% of births paid for by the Agency's Medi-Cal program were to women who were in the country illegally. Jeopardizing public health services for a segment of our community is unsafe, eventually more expensive, and fundamentally wrong.

Clearly, immigration has created many economic and social challenges for our future. To ensure the health condition of these immigrant populations, we need to improve the overall system of health care and overcome the imposing influence of poverty on health by ensuring universal access. We must also guard against stereotyping immigrants and recognize cultural barriers to access. We must eliminate these barriers in order to provide appropriate services. We need to recognize that acculturation toward U.S. society is not entirely a gain for health and that encouraging certain cultural values that influence healthy behaviors should be a strategy of large community programs. The California experience should get particular attention because it may serve as a model for future health care strategies among immigrant-rich populations. The real promise of reform in health care is to provide access for all our country's residents and thereby to reduce the eventual need for the costly treatment of disease.